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{{short description|Devaluation of currency over a period of time}}
{{Short description|Devaluation of money's purchasing power}}
{{about|a rise in general price level|the expansion of the early universe|Inflation (cosmology)|other uses|Inflation (disambiguation)}}
{{other uses}}{{Use mdy dates|date=September 2017}}
{{Use mdy dates}}
{{Macroeconomics sidebar}}
{{Macroeconomics sidebar}}
[[File:World inflation rate April 2023.png|thumb|Inflation rates among members of the [[International Monetary Fund]] in April 2023.]]
[[File:World inflation rate October 2025.png|thumb|upright=1.6|Global rates of inflation in October 2025 among [[International Monetary Fund]] members]]
[[File:UK and US 1989-present monthly CPI.svg|thumb|UK and US monthly inflation rates from January 1989 to the present.<ref>{{cite web |title=Consumer Price Index for All Urban Consumers (CPI-U): U.S. city average, by expenditure category, March 2022 |url=https://view.officeapps.live.com/op/view.aspx?src=https%3A%2F%2Fwww.bls.gov%2Fcpi%2Ftables%2Fsupplemental-files%2Fnews-release-table1-202203.xlsx&wdOrigin=BROWSELINK |access-date=12 March 2022 |website=[[Bureau of Labor Statistics]]}}</ref><ref>{{cite web |title=CPIH Annual Rate 00: All Items 2015=100 |url=https://www.ons.gov.uk/economy/inflationandpriceindices/timeseries/l55o/mm23 |access-date=13 April 2022 |website=[[Office for National Statistics]] |archive-date=April 24, 2022 |archive-url=https://web.archive.org/web/20220424051728/https://www.ons.gov.uk/economy/inflationandpriceindices/timeseries/l55o/mm23 |url-status=live }}</ref>]]
[[File:UK and US 1989-present monthly CPI.svg|thumb|upright=1.6|UK and US monthly inflation rates from January 1989<ref>{{cite web |date=March 2022 |title=Consumer Price Index for All Urban Consumers (CPI-U): U.S. city average, by expenditure category, March 2022 |url=https://view.officeapps.live.com/op/view.aspx?src=https%3A%2F%2Fwww.bls.gov%2Fcpi%2Ftables%2Fsupplemental-files%2Fnews-release-table1-202203.xlsx&wdOrigin=BROWSELINK |access-date=12 March 2022 |website=[[Bureau of Labor Statistics]]}}</ref><ref>{{cite web |date=13 April 2022 |title=CPIH Annual Rate 00: All Items 2015=100 |url=https://www.ons.gov.uk/economy/inflationandpriceindices/timeseries/l55o/mm23 |access-date=13 April 2022 |website=[[Office for National Statistics]] |archive-date=April 24, 2022 |archive-url=https://web.archive.org/web/20220424051728/https://www.ons.gov.uk/economy/inflationandpriceindices/timeseries/l55o/mm23 |url-status=live }}</ref>]]


In [[economics]], '''inflation''' is an increase in the general price level of goods and services in an economy.<ref>{{citation|url=https://www.clevelandfed.org/center-for-inflation-research/inflation-101/what-is-inflation-start|title=What Is Inflation?|publisher=Cleveland Federal Reserve|access-date=June 8, 2023|archive-date=March 30, 2021|archive-url=https://web.archive.org/web/20210330131140/https://www.clevelandfed.org/our-research/center-for-inflation-research/inflation-101/what-is-inflation-get-started|url-status=dead}}</ref><ref>{{cite web|url=https://www.bls.gov/bls/inflation.htm|title=Overview of BLS Statistics on Inflation and Prices : U.S. Bureau of Labor Statistics|publisher=Bureau of Labor Statistics|access-date=November 3, 2021|archive-date=December 10, 2021|archive-url=https://web.archive.org/web/20211210164020/https://www.bls.gov/bls/inflation.htm|url-status=live}}</ref><ref>{{cite news |title=How does the government measure inflation? |url=https://www.brookings.edu/blog/up-front/2021/06/28/how-does-the-government-measure-inflation/ |publisher=Brookings Institution |author1=Nasiha Salwati |author2=David Wessel |access-date=November 3, 2021 |archive-date=November 15, 2021 |archive-url=https://web.archive.org/web/20211115162420/https://www.brookings.edu/blog/up-front/2021/06/28/how-does-the-government-measure-inflation/ |url-status=live }}</ref><ref>{{cite web|url=https://www.federalreserve.gov/faqs/economy_14419.htm|title=The Fed – What is inflation and how does the Federal Reserve evaluate changes in the rate of inflation?|website=Board of Governors of the Federal Reserve System|access-date=November 3, 2021|archive-date=July 17, 2021|archive-url=https://web.archive.org/web/20210717231718/https://www.federalreserve.gov/faqs/economy_14419.htm|url-status=live}}</ref> When the general price level rises, each unit of [[currency]] buys fewer goods and services; consequently, inflation corresponds to a reduction in the [[purchasing power]] of money.<ref>[http://www.sedlabanki.is/?PageID=195 Why price stability?] {{webarchive |url=https://web.archive.org/web/20081014031836/http://www.sedlabanki.is/?PageID=195 }}, Central Bank of Iceland, Accessed on September 11, 2008.</ref><ref>Paul H. Walgenbach, Norman E. Dittrich and Ernest I. Hanson, (1973), Financial Accounting, New York: Harcourt Brace Javonovich, Inc. Page 429. "The Measuring Unit principle: The unit of measure in accounting shall be the base money unit of the most relevant currency. This principle also assumes that the unit of measure is stable; that is, changes in its general purchasing power are not considered sufficiently important to require adjustments to the basic financial statements."</ref> The opposite of inflation is [[deflation]], a decrease in the general price level of goods and services. The common measure of inflation is the '''inflation rate''', the annualized percentage change in a general [[price index]].<ref name="Mankiw 2002 22–32">{{Harvnb|Mankiw|2002|pp=22–32}}</ref> As prices faced by households do not all increase at the same rate, the [[consumer price index]] (CPI) is often used for this purpose. The [[employment cost index]] is also used for wages in the United States.
In [[economics]], '''inflation''' is an increase in the average price of goods and services in terms of [[money]].<ref>{{cite book |chapter= s.v. inflation |title= The Oxford English Dictionary: Being a Corrected Re-Issue of with An Introduction, Supplement and Bibliography of a New English Dictionary on Historical Principles |volume= 5 H-K |year= 1913 |place= Oxford |publisher= Clarendon Press |url= https://archive.org/details/in.ernet.dli.2015.99995/page/n5/mode/2up?view=theater |page= [https://archive.org/details/in.ernet.dli.2015.99995/page/n791/mode/2up?view=theater 267] |via= [[Internet Archive]] |access-date= 6 August 2025}}</ref><ref name=Romer>{{Harvnb|Romer|2019}}</ref>{{rp|579}} This increase is measured using a price index, typically a [[consumer price index]] (CPI).<ref>{{citation |title=What Is Inflation? |date=June 8, 2023 |url=https://www.clevelandfed.org/center-for-inflation-research/inflation-101/what-is-inflation-start |access-date=June 8, 2023 |archive-url=https://web.archive.org/web/20210330131140/https://www.clevelandfed.org/our-research/center-for-inflation-research/inflation-101/what-is-inflation-get-started |publisher=Cleveland Federal Reserve |archive-date=March 30, 2021}}.</ref><ref>{{cite web|url=https://www.bls.gov/bls/inflation.htm|title=Overview of BLS Statistics on Inflation and Prices: U.S. Bureau of Labor Statistics|publisher=Bureau of Labor Statistics|date=June 5, 2019|access-date=November 3, 2021|archive-date=December 10, 2021|archive-url=https://web.archive.org/web/20211210164020/https://www.bls.gov/bls/inflation.htm|url-status=live}}</ref><ref>{{cite news |last1=Salwati |first1=Nasiha |last2=Wessel |first2=David |date=June 28, 2021 |title=How does the government measure inflation? |publisher=Brookings Institution |url=https://www.brookings.edu/blog/up-front/2021/06/28/how-does-the-government-measure-inflation/ |url-status=live |access-date=November 3, 2021 |archive-url=https://web.archive.org/web/20211115162420/https://www.brookings.edu/blog/up-front/2021/06/28/how-does-the-government-measure-inflation/ |archive-date=November 15, 2021}}</ref><ref>{{cite web|url=https://www.federalreserve.gov/faqs/economy_14419.htm|title=The Fed – What is inflation and how does the Federal Reserve evaluate changes in the rate of inflation?|website=Board of Governors of the Federal Reserve System|date=September 9, 2016|access-date=November 3, 2021|archive-date=July 17, 2021|archive-url=https://web.archive.org/web/20210717231718/https://www.federalreserve.gov/faqs/economy_14419.htm|url-status=live}}</ref> When the general price level rises, each unit of [[currency]] buys fewer goods and services; consequently, inflation corresponds to a reduction in the [[purchasing power]] of money.<ref>[http://www.sedlabanki.is/?PageID=195 Why price stability?] {{webarchive |url=https://web.archive.org/web/20081014031836/http://www.sedlabanki.is/?PageID=195 |date=October 14, 2008}}, Central Bank of Iceland, Accessed on September 11, 2008.</ref><ref>Paul H. Walgenbach, Norman E. Dittrich and Ernest I. Hanson, (1973), Financial Accounting, New York: Harcourt Brace Javonovich, Incorporated. P. 429. "The Measuring Unit principle: The unit of measure in accounting shall be the base money unit of the most relevant currency. This principle also assumes that the unit of measure is stable; that is, changes in its general purchasing power are not considered sufficiently important to require adjustments to the basic financial statements."</ref> The opposite of inflation is [[deflation]], a decrease in the general price level of goods and services. The common measure of inflation is the '''inflation rate''', the annualized percentage change in a general [[price index]].<ref name=Mankiw2002>{{Harvnb|Mankiw|2002}}</ref>{{rp|22–32}}


There is disagreement among economists as to the causes of inflation. Low or moderate inflation is widely attributed to fluctuations in [[Real versus nominal value (economics)|real]] [[demand]] for goods and services or changes in available supplies such as during [[scarcities]].<ref>{{cite web|url=http://research.stlouisfed.org/fred2/series/MZMV|title=MZM velocity|access-date=September 13, 2014|archive-date=June 16, 2016|archive-url=https://web.archive.org/web/20160616221321/https://research.stlouisfed.org/fred2/series/MZMV|url-status=live}}</ref> Moderate inflation affects economies in both positive and negative ways. The negative effects would include an increase in the [[opportunity cost]] of holding money, uncertainty over future inflation, which may discourage investment and savings, and if inflation were rapid enough, shortages of [[Good (economics)|goods]] as consumers begin [[Hoarding (economics)|hoarding]] out of concern that prices will increase in the future. Positive effects include reducing [[unemployment]] due to [[Nominal rigidity|nominal wage rigidity]],<ref>{{Harvnb|Mankiw|2002|pp=238–255}}</ref> allowing the central bank greater freedom in carrying out [[monetary policy]], encouraging loans and investment instead of money hoarding, and avoiding the inefficiencies associated with deflation.
Changes in inflation are widely attributed to increases in the [[money supply]], fluctuations in [[Real versus nominal value (economics)|real]] [[demand]] for goods and services (also known as [[demand shock]]s, including changes in [[fiscal policy|fiscal]] or [[monetary policy]]), changes in available supplies such as during [[energy crisis|energy crises]] (also known as [[supply shock]]s), significant decreases in [[Interest rate|interest rates]] set by the [[central bank]], or changes in inflation expectations, which may be self-fulfilling.<ref name="Romer" /><ref name="Blanchard">{{Harvnb|Blanchard|2021}}</ref> Moderate inflation affects economies in both positive and negative ways. The negative effects would include an increase in the [[opportunity cost]] of holding money; uncertainty over future inflation, which may discourage investment and savings; and, if inflation were rapid enough, shortages of [[Good (economics)|goods]] as consumers begin [[Hoarding (economics)|hoarding]] out of concern that prices will increase in the future. Positive effects include reducing unemployment due to [[Nominal rigidity|nominal wage rigidity]],<ref name=Mankiw2002/>{{rp|238–255}} allowing the central bank greater freedom in carrying out [[monetary policy]], encouraging loans and investment instead of money hoarding, and avoiding the inefficiencies associated with deflation.


Today, most{{Weasel inline}} economists favour a low and steady rate of inflation.<ref name="econjournalwatch.org">Hummel, Jeffrey Rogers. "Death and Taxes, Including Inflation: the Public versus Economists" (January 2007).[http://econjwatch.org/articles/death-and-taxes-including-inflation-the-public-versus-economists] {{Webarchive|url=https://web.archive.org/web/20131225042059/http://econjwatch.org/articles/death-and-taxes-including-inflation-the-public-versus-economists}} p. 56</ref> Low (as opposed to zero or [[Deflation|negative]]) inflation reduces the probability of economic [[recessions]] by enabling the labor market to adjust more quickly in a downturn and reduces the risk that a [[liquidity trap]] prevents [[monetary policy]] from stabilizing the economy, while avoiding the costs associated with high inflation.<ref name="aeaweb.org">"[http://www.aeaweb.org/articles.php?doi=10.1257/089533003772034934 Escaping from a Liquidity Trap and Deflation: The Foolproof Way and Others] {{Webarchive|url=https://web.archive.org/web/20140226234952/http://www.aeaweb.org/articles.php?doi=10.1257%2F089533003772034934 }}" Lars E.O. Svensson, ''Journal of Economic Perspectives'', Volume 17, Issue 4 Fall 2003, pp. 145–166</ref> The task of keeping the rate of inflation low and stable is usually given to [[Monetary authority|monetary authorities]]. Generally, these monetary authorities are the [[central bank]]s that control monetary policy through the setting of [[interest rate]]s, by carrying out [[open market operation]]s and (more rarely) changing commercial bank [[reserve requirements]].<ref name=Taylor>{{cite book |last=Taylor |first=Timothy |title=Principles of Economics |publisher=Freeload Press |isbn=978-1-930789-05-0}}</ref>
Today, most economists favour a low and steady rate of inflation. Low (as opposed to zero or [[Deflation|negative]]) inflation reduces the likelihood of economic [[recessions]] by enabling the labor market to adjust more quickly and reduces the risk that a [[liquidity trap]] prevents [[monetary policy]] from stabilizing the economy, while also avoiding the costs associated with high inflation.<ref name="aeaweb.org">{{Cite journal |last=Svensson |first=Lars E. O. |date=December 2003 |title=Escaping from a Liquidity Trap and Deflation: The Foolproof Way and Others |journal=Journal of Economic Perspectives |language=en |volume=17 |issue=4 |pages=145–166 |doi=10.1257/089533003772034934 |s2cid=17420811 |issn=0895-3309|doi-access=free }}</ref> The task of keeping the rate of inflation low and stable is usually given to central banks that control monetary policy, normally through the setting of interest rates and by carrying out [[open market operation]]s.<ref name=Blanchard/>


== Terminology ==
== Terminology ==
The term originates from the Latin ''inflare'' (to blow into or inflate) and was initially used in America in 1838 with regard to inflating the currency.<ref name=PeterB>{{cite book |last=Bernholz |first=Peter |url=https://www.elgaronline.com/view/9781784717629.00007.xml |title=Introduction |year=2015 |publisher=Edward Elgar Publishing |isbn=978-1-78471-763-6 |language=en-US |access-date=June 9, 2022 |archive-date=June 18, 2021 |archive-url=https://web.archive.org/web/20210618191304/https://www.elgaronline.com/view/9781784717629.00007.xml |url-status=live }}</ref> The term was used "not in reference to something that happens to prices, but as something that happens to a paper currency".<ref name="bryan">Bryan, Michael F., [https://www.clevelandfed.org/newsroom-and-events/publications/economic-commentary/economic-commentary-archives/1997-economic-commentaries/ec-19971015-on-the-origin-and-evolution-of-the-word-inflation.aspx "On the Origin and Evolution of the Word Inflation"] {{Webarchive|url=https://web.archive.org/web/20211028064428/https://www.clevelandfed.org/newsroom-and-events/publications/economic-commentary/economic-commentary-archives/1997-economic-commentaries/ec-19971015-on-the-origin-and-evolution-of-the-word-inflation.aspx }}, ''Federal Reserve Bank of Cleveland, Economic Commentary,'' 15 October 1997.</ref> The resulting imbalance between the quantity of money and the amount needed for trade caused prices to increase. Over time, the term ''inflation'' has evolved to refer to increases in the price level; an increase in the money supply may be called [[monetary inflation]] to distinguish it from rising prices, which for clarity may be called "price inflation".<ref name="bryan"/>
The term originates from the Latin ''inflare'' (to blow into or inflate). Conceptually, inflation refers to the general trend of prices, not changes in any specific price. For example, if people choose to buy more cucumbers than tomatoes, cucumbers consequently become more expensive and tomatoes less expensive. These changes are not related to inflation; they reflect a shift in tastes. Inflation is related to the value of currency itself. When currency was linked with gold, if new gold deposits were found, the price of gold and the value of currency would fall, and consequently, the prices of all other goods would become higher.<ref>{{cite web|url=https://www.vox.com/cards/inflation-definition-and-explanation/inflation-explanation|title=What is inflation? – Inflation, explained |date=July 25, 2014|work=Vox|access-date=September 13, 2014|archive-date=August 4, 2014|archive-url=https://web.archive.org/web/20140804103626/http://www.vox.com/cards/inflation-definition-and-explanation/inflation-explanation|url-status=live}}</ref>
 
Conceptually, inflation refers to the general trend of prices, not changes in any specific price. For example, if people choose to buy more cucumbers than tomatoes, cucumbers consequently become more expensive and tomatoes cheaper. These changes are not related to inflation; they reflect a shift in tastes. Inflation is related to the value of currency itself. When currency was linked with gold, if new gold deposits were found, the price of gold and the value of currency would fall, and consequently, prices of all other goods would become higher.<ref>{{cite web|url=https://www.vox.com/cards/inflation-definition-and-explanation/inflation-explanation|title=What is inflation? – Inflation, explained – Vox|work=Vox|access-date=September 13, 2014|archive-date=August 4, 2014|archive-url=https://web.archive.org/web/20140804103626/http://www.vox.com/cards/inflation-definition-and-explanation/inflation-explanation|url-status=live}}</ref>


===Classical economics===
===Classical economics===
By the nineteenth century, economists categorised three separate factors that cause a rise or fall in the price of goods: a change in the ''[[Value (economics)|value]]'' or production costs of the good, a change in the ''price of money'' which then was usually a fluctuation in the [[commodity]] price of the metallic content in the currency, and ''currency depreciation'' resulting from an increased supply of currency relative to the quantity of redeemable metal backing the currency. Following the proliferation of private [[banknote]] currency printed during the [[American Civil War]], the term "inflation" started to appear as a direct reference to the ''currency depreciation'' that occurred as the quantity of redeemable banknotes outstripped the quantity of metal available for their redemption. At that time, the term inflation referred to the [[devaluation]] of the currency, and not to a rise in the price of goods.<ref name="Bryan">{{cite journal|first=Michael F.|last=Bryan|url=https://www.clevelandfed.org/newsroom-and-events/publications/economic-commentary/economic-commentary-archives/1997-economic-commentaries/ec-19971015-on-the-origin-and-evolution-of-the-word-inflation.aspx|publisher=Federal Reserve Bank of Cleveland, Economic Commentary|title=On the Origin and Evolution of the Word "Inflation"|journal=Economic Commentary|issue=October 15, 1997|access-date=May 22, 2017|archive-date=October 28, 2021|archive-url=https://web.archive.org/web/20211028064428/https://www.clevelandfed.org/newsroom-and-events/publications/economic-commentary/economic-commentary-archives/1997-economic-commentaries/ec-19971015-on-the-origin-and-evolution-of-the-word-inflation.aspx|url-status=live}}</ref> This relationship between the over-supply of banknotes and a resulting [[depreciation]] in their value was noted by earlier classical economists such as [[David Hume]] and [[David Ricardo]], who would go on to examine and debate what effect a currency devaluation (later termed ''[[monetary inflation]]'') has on the price of goods (later termed ''price inflation'', and eventually just ''inflation'').<ref>Mark Blaug, "[https://books.google.com/books?id=4nd6alor2goC&dq=bullionist+inflation&pg=PA128 Economic Theory in Retrospect] {{Webarchive|url=https://web.archive.org/web/20230203015223/https://books.google.com/books?id=4nd6alor2goC&pg=PA127&lpg=PA127&dq=bullionist+inflation&source=web&ots=mG3_PT_O6q&sig=ViD-klPJPpaZxCBjdcPKh9zlwyU&hl=en&sa=X&oi=book_result&resnum=5&ct=result#PPA128,M1 }}", p. 129: "...this was the cause of inflation, or, to use the language of the day, 'the depreciation of banknotes.'"</ref>
By the nineteenth century, economists categorised three separate factors that cause a rise or fall in the price of goods: a change in the ''[[Value (economics)|value]]'' or production costs of the good, a change in the ''price of money'' which then was usually a fluctuation in the [[commodity]] price of the metallic content in the currency, and ''[[currency depreciation]]'' resulting from an increased supply of currency relative to the quantity of redeemable metal backing the currency. Following the proliferation of private [[banknote]] currency printed during the [[American Civil War]], the term "inflation" started to appear as a direct reference to the ''currency depreciation'' that occurred as the quantity of redeemable banknotes outstripped the quantity of metal available for their redemption. At that time, the term inflation referred to the [[devaluation]] of the currency, and not to a rise in the price of goods.<ref>{{cite journal|first=Michael F.|last=Bryan|url=https://www.clevelandfed.org/newsroom-and-events/publications/economic-commentary/economic-commentary-archives/1997-economic-commentaries/ec-19971015-on-the-origin-and-evolution-of-the-word-inflation.aspx|publisher=Federal Reserve Bank of Cleveland, Economic Commentary|date=October 15, 1997|title=On the Origin and Evolution of the Word 'Inflation'|journal=Economic Commentary|issue=October 15, 1997|access-date=May 22, 2017|archive-date=October 28, 2021|archive-url=https://web.archive.org/web/20211028064428/https://www.clevelandfed.org/newsroom-and-events/publications/economic-commentary/economic-commentary-archives/1997-economic-commentaries/ec-19971015-on-the-origin-and-evolution-of-the-word-inflation.aspx|url-status=live}}</ref> This relationship between the over-supply of banknotes and a resulting [[depreciation]] in their value was noted by earlier classical economists such as [[David Hume]] and [[David Ricardo]], who would go on to examine and debate what effect a currency devaluation has on the price of goods.<ref>{{Cite book |last=Blaug |first=Mark |url=https://books.google.com/books?id=4nd6alor2goC&dq=bullionist+inflation&pg=PA128 |title=Economic Theory in Retrospect |date=1997-03-27 |publisher=Cambridge University Press |isbn=978-0-521-57701-4 |page=129 |language=en |quote=...this was the cause of inflation, or, to use the language of the day, 'the depreciation of banknotes.'}}</ref>


=== Related concepts ===
=== Related concepts ===
Other economic concepts related to inflation include: [[deflation]]{{snd}}a fall in the general price level; [[disinflation]]{{snd}}a decrease in the rate of inflation; [[hyperinflation]]{{snd}}an out-of-control inflationary spiral; [[stagflation]]{{snd}}a combination of inflation, slow economic growth and high unemployment; [[reflation]]{{snd}}an attempt to raise the general level of prices to counteract deflationary pressures; and [[asset price inflation]]{{snd}}a general rise in the prices of financial assets without a corresponding increase in the prices of goods or services; [[agflation]]{{snd}}an advanced increase in the price for food and industrial agricultural crops when compared with the general rise in prices.
Other economic concepts related to inflation include: [[deflation]]{{snd}}a fall in the general price level;<ref>{{Cite news |last=Ashford |first=Kate |date=2023-11-16 |title=What Is Deflation? Why Is It Bad For The Economy? |url=https://www.forbes.com/advisor/investing/what-is-deflation/#:~:text=Deflation%20Definition,in%20prices%20across%20the%20economy.https://www.forbes.com/advisor/investing/what-is-deflation/#:~:text=Deflation%20Definition,in%20prices%20across%20the%20economy. |access-date=2024-01-30 |work=Forbes Advisor |language=en-US}}</ref> [[disinflation]]{{snd}}a decrease in the rate of inflation;<ref>{{Cite web |title=Disinflation: Definition, How It Works, Triggers, and Example |url=https://www.investopedia.com/terms/d/disinflation.asp |access-date=2024-01-30 |website=Investopedia |language=en}}</ref> [[hyperinflation]]{{snd}}an out-of-control inflationary spiral;<ref>{{Cite web |title=Hyperinflation |url=https://corporatefinanceinstitute.com/resources/economics/hyperinflation/ |access-date=2024-01-30 |website=Corporate Finance Institute |language=en-US}}</ref> [[stagflation]]{{snd}}a combination of inflation, slow economic growth and high unemployment;<ref>{{Cite web |title=What Is Stagflation, What Causes It, and Why Is It Bad? |url=https://www.investopedia.com/terms/s/stagflation.asp |access-date=2024-01-30 |website=Investopedia |language=en}}</ref> [[reflation]]{{snd}}an attempt to raise the general level of prices to counteract deflationary pressures;<ref>{{Cite web |title=What Is Reflation? |url=https://www.thebalancemoney.com/what-is-reflation-5210962 |access-date=2024-01-30 |website=The Balance |language=en}}</ref> [[asset price inflation]]{{snd}}a general rise in the prices of financial assets without a corresponding increase in the prices of goods or services;<ref>{{Cite web |title=Asset-Price Inflation vs. Economic Growth |url=https://www.investopedia.com/ask/answers/032715/what-difference-between-assetprice-inflation-and-economic-growth.asp |access-date=2024-01-30 |website=Investopedia |language=en}}</ref> and [[agflation]]{{snd}}an advanced increase in the [[Food inflation|price for food]] and industrial agricultural crops when compared with the general rise in prices.<ref>{{Cite web |title=Agflation: What It Means, How It Works, Impact |url=https://www.investopedia.com/terms/a/agflation.asp |access-date=2024-01-30 |website=Investopedia |language=en}}</ref>


More specific forms of inflation refer to sectors whose prices vary semi-independently from the general trend. "House price inflation" applies to changes in the [[house price index]]<ref>[https://www.gov.uk/government/statistics/announcements/uk-house-price-index-november-2021 UK House Price Index] {{Webarchive|url=https://web.archive.org/web/20211028065426/https://www.gov.uk/government/statistics/announcements/uk-house-price-index-november-2021 }}.</ref> while "energy inflation" is dominated by the costs of oil and gas.<ref>Ieva Rubene and Gerrit Koester, [https://www.ecb.europa.eu/pub/economic-bulletin/focus/2021/html/ecb.ebbox202103_04~0a0c8f0814.en.html "Recent dynamics in energy inflation: the role of base effects and taxes"] {{Webarchive|url=https://web.archive.org/web/20211115170910/https://www.ecb.europa.eu/pub/economic-bulletin/focus/2021/html/ecb.ebbox202103_04~0a0c8f0814.en.html }} (2021).</ref>
More specific forms of inflation refer to sectors whose prices vary semi-independently from the general trend. "House price inflation" applies to changes in the [[house price index]]<ref>{{Cite web |title=UK House Price Index: November 2021 |url=https://www.gov.uk/government/statistics/uk-house-price-index-november-2021 |access-date=2023-11-19 |website=GOV.UK |language=en}}</ref> while "energy inflation" is dominated by the costs of oil and gas.<ref>{{Cite journal |last1=Rubene |first1=Ieva |last2=Koester |first2=Gerrit |date=2021-05-06 |title=Recent dynamics in energy inflation: the role of base effects and taxes|journal=ECB Economic Bulletin |issue=3 |url=https://www.ecb.europa.eu/pub/economic-bulletin/focus/2021/html/ecb.ebbox202103_04~0a0c8f0814.en.html |language=en}}</ref>


==History==
==History==
[[File:US Historical Inflation Ancient.svg|thumb|350px|US historical inflation (in blue) and deflation (in green) from the mid-17th century to the beginning of the 21st.]]
[[File:US Historical Inflation Ancient.svg|thumb|upright=1.6|US historical inflation (in blue) and deflation (in green) from the mid-17th century to the beginning of the 21st]]


Historically, when [[commodity money]] was used, periods of inflation and deflation would alternate depending on the condition of the economy. However, when large prolonged infusions of gold or silver into an economy occurred, this could lead to long periods of inflation.
===Overview===


The adoption of [[fiat currency]] by many countries, from the 18th century onwards, made much larger variations in the supply of money possible. Rapid increases in the [[money supply]] have taken place a number of times in countries experiencing political crises, producing [[hyperinflation]]s{{snd}}episodes of extreme inflation rates much higher than those observed in earlier periods of [[commodity money]]. The [[hyperinflation in the Weimar Republic]] of Germany is a notable example. Currently, the [[hyperinflation]] in [[Venezuela]] is the highest in the world, with an annual inflation rate of 833,997% as of October 2018.<ref>{{cite news |last1=Corina |first1=Pons |last2=Luc |first2=Cohen |last3=O'Brien |first3=Rosalba |title=Venezuela's annual inflation hit 833,997 percent in October: Congress |url=https://www.reuters.com/article/us-venezuela-economy/venezuelas-annual-inflation-hit-833997-percent-in-october-congress-idUSKCN1NC2F9 |access-date=9 November 2018 |work=Reuters |archive-date=December 12, 2021 |archive-url=https://web.archive.org/web/20211212194638/https://www.reuters.com/article/us-venezuela-economy/venezuelas-annual-inflation-hit-833997-percent-in-october-congress-idUSKCN1NC2F9 |url-status=live }}</ref>
Inflation has been a feature of history during the entire period when money has been used as a means of payment. One of the earliest documented inflations occurred in [[Alexander the Great]]'s empire 330 BC.<ref name=parkin>{{cite journal |last1=Parkin |first1=Michael |title=Inflation |journal=The New Palgrave Dictionary of Economics |date=2008 |pages=1–14 |doi=10.1057/978-1-349-95121-5_888-2|isbn=978-1-349-95121-5 }}</ref> Historically, when [[commodity money]] was used, periods of inflation and deflation would alternate depending on the condition of the economy. However, when large, prolonged infusions of gold or silver into an economy occurred, this could lead to long periods of inflation.


Historically, inflations of varying magnitudes have occurred from the price revolution of the 16th century, which was driven by the flood of gold and particularly silver seized and mined by the Spaniards in Latin America, to the largest paper money inflation of all time in Hungary after World War II.<ref name=PeterB />
The adoption of [[fiat currency]] by many countries, from the 18th century onwards, made much larger variations in the supply of money possible.<ref>{{Cite web |title=Fiat Money: What It Is, How It Works, Example, Pros & Cons |url=https://www.investopedia.com/terms/f/fiatmoney.asp |access-date=2024-01-30 |website=Investopedia |language=en}}</ref> Rapid increases in the [[money supply]] have taken place a number of times in countries experiencing political crises, producing [[hyperinflation]]s{{snd}}episodes of extreme inflation rates much higher than those observed in earlier periods of [[commodity money]]. The [[hyperinflation in the Weimar Republic]] of Germany is a notable example. The [[hyperinflation]] in Venezuela is the highest in the world, with an annual inflation rate of 833,997% as of October 2018.<ref>{{cite news |last1=Corina |first1=Pons |last2=Luc |first2=Cohen |last3=O'Brien |first3=Rosalba |title=Venezuela's annual inflation hit 833,997 percent in October: Congress |url=https://www.reuters.com/article/us-venezuela-economy/venezuelas-annual-inflation-hit-833997-percent-in-october-congress-idUSKCN1NC2F9 |access-date=9 November 2018 |work=Reuters |date=7 November 2018 |archive-date=December 12, 2021 |archive-url=https://web.archive.org/web/20211212194638/https://www.reuters.com/article/us-venezuela-economy/venezuelas-annual-inflation-hit-833997-percent-in-october-congress-idUSKCN1NC2F9 |url-status=live }}</ref>


However, since the 1980s, inflation has been held low and stable in countries with independent [[central bank]]s. This has led to a moderation of the [[business cycle]] and a reduction in variation in most macroeconomic indicators{{snd}}an event known as the [[Great Moderation]].<ref>{{cite news |url=http://www.timesonline.co.uk/tol/comment/columnists/article1294376.ece |title=Welcome to 'the Great Moderation' |first=Gerard |last=Baker |work=The Times |publisher=Times Newspapers |location=London |issn=0140-0460 |access-date=15 April 2011 |archive-date=December 14, 2021 |archive-url=https://web.archive.org/web/20211214175030/https://www.thetimes.co.uk/ |url-status=live }}</ref>
Historically, inflations of varying magnitudes have occurred, interspersed with corresponding deflationary periods,<ref name=parkin/> from the [[price revolution]] of the 16th century, which was driven by the flood of gold and particularly silver seized and mined by the Spaniards in Latin America, to the largest paper money inflation of all time in Hungary after World War II.<ref>{{cite book |last=Bernholz |first=Peter |url=https://www.elgaronline.com/view/9781784717629.00007.xml |title=Introduction |year=2015 |publisher=Edward Elgar Publishing |isbn=978-1-78471-763-6 |language=en-US |access-date=June 9, 2022 |archive-date=June 18, 2021 |archive-url=https://web.archive.org/web/20210618191304/https://www.elgaronline.com/view/9781784717629.00007.xml |url-status=live }}</ref>


===Historical inflationary periods===
However, since the 1980s, inflation has been held low and stable in countries with independent [[central bank]]s. This has led to a moderation of the [[business cycle]] and a reduction in variation in most macroeconomic indicators{{snd}}an event known as the [[Great Moderation]].<ref>{{cite news |url=http://www.timesonline.co.uk/tol/comment/columnists/article1294376.ece |title=Welcome to 'the Great Moderation' |first=Gerard |last=Baker |work=The Times |date=2007-01-19 |publisher=Times Newspapers |location=London |issn=0140-0460 |access-date=15 April 2011 |archive-date=December 14, 2021 |archive-url=https://web.archive.org/web/20211214175030/https://www.thetimes.co.uk/ }}</ref>


{{multiple image
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Fineness_of_early_Roman_Imperial_silver_coins.png
Fineness_of_early_Roman_Imperial_silver_coins.png
  | caption1 = Silver purity through time in early Roman imperial silver coins. To increase the number of silver coins in circulation while short on silver, the Roman imperial government repeatedly [[debasement|debased]] the coins. They melted relatively pure silver coins and then struck new silver coins of lower purity but of nominally equal value. Silver coins were relatively pure before Nero (AD 54-68), but by the 270s had hardly any silver left.
  | caption1 = Silver purity through time in early Roman imperial silver coins. To increase the number of silver coins in circulation while short on silver, the Roman imperial government repeatedly [[debasement|debased]] the coins. They melted relatively pure silver coins and then struck new silver coins of lower purity but of nominally equal value. Silver coins were relatively pure before Nero (AD 54–68), but by the 270s had hardly any silver left.
  | image2 = Decline_of_the_antoninianus.jpg
  | image2 = Decline_of_the_antoninianus.jpg
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Rapid increases in the quantity of money or in the overall [[money supply]] have occurred in many different societies throughout history, changing with different forms of money used.<ref>{{Cite news|last=Dobson |first=Roger |title=How Alexander caused a great Babylon inflation |newspaper=[[The Independent]] |url=https://www.independent.co.uk/news/world/europe/how-alexander-caused-a-great-babylon-inflation-671072.html |archive-url=https://web.archive.org/web/20110515070120/http://www.independent.co.uk/news/world/europe/how-alexander-caused-a-great-babylon-inflation-671072.html |archive-date=May 15, 2011 |access-date=April 12, 2010 |url-status=dead |df=mdy-all }}</ref><ref>{{Cite book  | last = Harl  | first = Kenneth W.  | author-link = Kenneth W. Harl  | title = Coinage in the Roman Economy, 300 B.C. to A.D. 700  | place = [[Baltimore]]  | publisher = [[The Johns Hopkins University Press]]  | year=1996  | isbn = 0-8018-5291-9  }}</ref> For instance, when silver was used as currency, the government could collect silver coins, melt them down, mix them with other metals such as copper or lead and reissue them at the same [[Real versus nominal value (economics)|nominal value]], a process known as [[debasement]]. At the ascent of [[Nero]] as Roman emperor in AD 54, the [[denarius]] contained more than 90% silver, but by the 270s hardly any silver was left. By diluting the silver with other metals, the government could issue more coins without increasing the amount of silver used to make them. When the cost of each coin is lowered in this way, the government profits from an increase in [[seigniorage]].<ref>{{cite web |url=http://www.mint.ca/royalcanadianmintpublic/RcmImageLibrary.aspx?filename=RCM_AR06_E.pdf |title=Annual Report (2006), Royal Canadian Mint, p. 4 |publisher=Mint.ca |access-date=May 21, 2011 |archive-date=December 17, 2008 |archive-url=https://web.archive.org/web/20081217200449/http://www.mint.ca/royalcanadianmintpublic/RcmImageLibrary.aspx?filename=RCM_AR06_E.pdf |url-status=live }}</ref> This practice would increase the money supply but at the same time the relative value of each coin would be lowered. As the relative value of the coins becomes lower, consumers would need to give more coins in exchange for the same goods and services as before. These goods and services would experience a price increase as the value of each coin is reduced.<ref>Frank Shostak, "[https://mises.org/story/3018 Commodity Prices and Inflation: What's the connection", Mises Institute] {{Webarchive|url=https://web.archive.org/web/20090807064142/http://mises.org/story/3018 }}</ref>
===Ancient Europe===
 
Alexander the Great's conquest of the [[Achaemenid Empire|Persian Empire]] in 330 BC was followed by one of the earliest documented inflation periods in the ancient world.<ref name=parkin/> Rapid increases in the quantity of money or in the overall [[money supply]] have occurred in many different societies throughout history, changing with different forms of money used.<ref>{{Cite news|last=Dobson |first=Roger |title=How Alexander caused a great Babylon inflation |newspaper=[[The Independent]] |date=January 27, 2002 |url=https://www.independent.co.uk/news/world/europe/how-alexander-caused-a-great-babylon-inflation-671072.html |archive-url=https://web.archive.org/web/20110515070120/http://www.independent.co.uk/news/world/europe/how-alexander-caused-a-great-babylon-inflation-671072.html |archive-date=May 15, 2011 |access-date=April 12, 2010 }}</ref><ref>{{Cite book  | last = Harl  | first = Kenneth W.  | author-link = Kenneth W. Harl  | title = Coinage in the Roman Economy, 300 B.C. to A.D. 700  | place = [[Baltimore]]  | publisher = [[The Johns Hopkins University Press]]  | year=1996  | isbn = 0-8018-5291-9  }}</ref> For instance, when silver was used as currency, the government could collect silver coins, melt them down, mix them with other, less valuable metals such as copper or lead and reissue them at the same [[Real versus nominal value (economics)|nominal value]], a process known as [[debasement]]. At the ascent of [[Nero]] as Roman emperor in AD 54, the [[denarius]] contained more than 90% silver, but by the 270s hardly any silver was left. By diluting the silver with other metals, the government could issue more coins without increasing the amount of silver used to make them. When the cost of each coin is lowered in this way, the government profits from an increase in [[seigniorage]].<ref>{{cite web |url=http://www.mint.ca/royalcanadianmintpublic/RcmImageLibrary.aspx?filename=RCM_AR06_E.pdf |title=Annual Report (2006), Royal Canadian Mint, p. 4 |publisher=Mint.ca |access-date=May 21, 2011 |archive-date=December 17, 2008 |archive-url=https://web.archive.org/web/20081217200449/http://www.mint.ca/royalcanadianmintpublic/RcmImageLibrary.aspx?filename=RCM_AR06_E.pdf |url-status=live }}</ref> This practice would increase the money supply but at the same time the relative value of each coin would be lowered. As the relative value of the coins becomes lower, consumers would need to give more coins in exchange for the same goods and services as before. These goods and services would experience a price increase as the value of each coin is reduced.<ref>{{Cite web |last=Shostak |first=Frank |date=2008-06-16 |title=Commodity Prices and Inflation: What's the Connection? |url=https://mises.org/library/commodity-prices-and-inflation-whats-connection |access-date=2023-11-19 |website=Mises Institute |language=en}}</ref> Again at the end of the third century AD during the reign of [[Diocletian]], the [[Roman Empire]] experienced rapid inflation.<ref name=parkin/>


===Ancient China===
===Ancient China===
[[Song dynasty]] China introduced the practice of printing paper money to create [[fiat currency]].<ref name="Glahn">{{cite book|author=Richard von Glahn|title=Fountain of Fortune: Money and Monetary Policy in China, 1000–1700|year=1996|publisher=University of California Press|isbn=978-0-520-20408-9|page=48}}</ref> During the Mongol [[Yuan dynasty]], the government spent a great deal of money fighting [[Mongol conquests|costly wars]], and reacted by printing more money, leading to inflation.<ref name="Ropp2010">{{cite book|author=Paul S. Ropp|title=China in World History|year=2010|publisher=Oxford University Press|isbn=978-0-19-517073-3|pages=82}}</ref> Fearing the inflation that plagued the Yuan dynasty, the [[Ming dynasty]] initially rejected the use of paper money, and reverted to using copper coins.<ref name="Bernholz">{{cite book|author=Peter Bernholz|title=Monetary Regimes and Inflation: History, Economic and Political Relationships|year=2003|publisher=Edward Elgar Publishing|isbn=978-1-84376-155-6|pages=53–55}}</ref>
[[Song dynasty]] China introduced the practice of printing paper money to create [[fiat currency]].<ref>{{cite book |author=von Glahn |first=Richard |title=Fountain of Fortune: Money and Monetary Policy in China, 1000–1700 |publisher=University of California Press |year=1996 |isbn=978-0-520-20408-9 |page=48}}</ref> During the Mongol [[Yuan dynasty]], the government spent a great deal of money fighting [[Mongol conquests|costly wars]], and reacted by printing more money, leading to inflation.<ref>{{cite book |author=Ropp |first=Paul S. |title=China in World History |publisher=Oxford University Press |year=2010 |isbn=978-0-19-517073-3 |page=82}}</ref> Fearing the inflation that plagued the Yuan dynasty, the [[Ming dynasty]] initially rejected the use of paper money, and reverted to using copper coins.<ref>{{cite book |author=Bernholz |first=Peter |title=Monetary Regimes and Inflation: History, Economic and Political Relationships |publisher=Edward Elgar Publishing |year=2003 |isbn=978-1-84376-155-6 |pages=53–55}}</ref>


===Medieval Egypt===
===Medieval Egypt===
During the [[Mali Empire|Malian]] king [[Mansa Musa]]'s [[hajj]] to [[Mecca]] in 1324, he was reportedly accompanied by a [[camel train]] that included thousands of people and nearly a hundred camels. When he passed through [[Cairo]], he spent or gave away so much gold that it depressed its price in Egypt for over a decade,<ref>[https://web.archive.org/web/20060524015912/http://www.blackhistorypages.net/pages/mansamusa.php Mansa Musa]. Black History Pages</ref> reducing its purchasing power. A contemporary Arab historian remarked about Mansa Musa's visit:
During the [[Mali Empire|Malian]] king [[Mansa Musa]]'s [[hajj]] to [[Mecca]] in 1324, he was reportedly accompanied by a [[camel train]] that included thousands of people and nearly a hundred camels. When he passed through [[Cairo]], he spent or gave away so much gold that it depressed its price in Egypt for over a decade,<ref>{{Cite web |date=2006-05-24 |title=Mansa Musa |url=http://www.blackhistorypages.net/pages/mansamusa.php |access-date=2023-11-19 |archive-url=https://web.archive.org/web/20060524015912/http://www.blackhistorypages.net/pages/mansamusa.php |archive-date=May 24, 2006 }}</ref> reducing its purchasing power. A contemporary Arab historian remarked about Mansa Musa's visit:


{{blockquote|Gold was at a high price in Egypt until they came in that year. The [[mithqal]] did not go below 25 [[dirham]]s and was generally above, but from that time its value fell and it cheapened in price and has remained cheap till now. The mithqal does not exceed 22 dirhams or less. This has been the state of affairs for about twelve years until this day by reason of the large amount of gold which they brought into Egypt and spent there [...].|sign=[[Chihab Al-Umari]]|source=Kingdom of Mali<ref>{{cite web |title=Kingdom of Mali&nbsp;– Primary Source Documents |url=http://www.bu.edu/africa/outreach/resources/k_o_mali/ |website=African studies Center |publisher=[[Boston University]] |access-date=30 January 2012 |archive-date=November 24, 2015 |archive-url=https://web.archive.org/web/20151124051633/http://www.bu.edu/africa/outreach/resources/k_o_mali/ |url-status=live }}</ref>}}
{{blockquote|Gold was at a high price in Egypt until they came in that year. The [[mithqal]] did not go below 25 [[dirham]]s and was generally above, but from that time its value fell and it cheapened in price and has remained cheap till now. The mithqal does not exceed 22 dirhams or less. This has been the state of affairs for about twelve years until this day by reason of the large amount of gold which they brought into Egypt and spent there [...].|sign=[[Chihab Al-Umari]]|source=Kingdom of Mali<ref>{{cite web |title=Kingdom of Mali&nbsp;– Primary Source Documents |url=http://www.bu.edu/africa/outreach/resources/k_o_mali/ |website=African studies Center |publisher=[[Boston University]] |access-date=30 January 2012 |archive-date=November 24, 2015 |archive-url=https://web.archive.org/web/20151124051633/http://www.bu.edu/africa/outreach/resources/k_o_mali/ |url-status=live }}</ref>}}


==="Price revolution" in Western Europe===
=== Medieval age and "price revolution" in Western Europe===
 
There is no reliable evidence of inflation in Europe for the thousand years that followed the fall of the Roman Empire, but from the [[Middle Ages]] onwards reliable data do exist. Mostly, the medieval inflation episodes were modest, and there was a tendency for inflationary periods to be followed by deflationary periods.<ref name=parkin/>


From the second half of the 15th century to the first half of the 17th, Western Europe experienced a major inflationary cycle referred to as the "[[price revolution]]",<ref>[[Earl J. Hamilton]], ''American Treasure and the Price Revolution in Spain, 1501–1650'' Harvard Economic Studies, 43 (Cambridge, Massachusetts: [[Harvard University Press]], 1934)</ref><ref>{{cite web|url=http://www.chass.utoronto.ca/ecipa/archive/UT-ECIPA-MUNRO-99-02.pdf|archive-url=https://web.archive.org/web/20090306002320/http://www.chass.utoronto.ca/ecipa/archive/UT-ECIPA-MUNRO-99-02.pdf |url-status=dead |title=John Munro: ''The Monetary Origins of the 'Price Revolution':South Germany Silver Mining, Merchant Banking, and Venetian Commerce, 1470–1540'', Toronto 2003|archive-date=March 6, 2009}}</ref> with prices on average rising perhaps sixfold over 150 years. This is often attributed to the influx of gold and silver from the [[New World]] into [[Habsburg Spain]],<ref>{{cite book |author=Walton, Timothy R. |title=The Spanish Treasure Fleets |publisher=Pineapple Press (FL) |year= 1994|page=85 |isbn=1-56164-049-2}}</ref> with wider availability of [[Silver coin|silver]] in previously [[Great Bullion Famine|cash-starved Europe]] causing widespread inflation.<ref>{{Cite journal|url=https://ideas.repec.org/p/bsl/wpaper/2007-12.html|title=The Price Revolution in the 16th Century: Empirical Results from a Structural Vectorautoregression Model|first1=Peter|last1=Bernholz|first2=Peter|last2=Kugler|journal=Working Papers|via=ideas.repec.org|access-date=March 31, 2015|archive-date=April 25, 2021|archive-url=https://web.archive.org/web/20210425223334/https://ideas.repec.org/p/bsl/wpaper/2007-12.html|url-status=live}}</ref><ref>{{cite book |author=Tracy, James D. |title=Handbook of European History 1400–1600: Late Middle Ages, Renaissance, and Reformation |publisher=Brill Academic Publishers |location=Boston |year= 1994|page=655 |isbn=90-04-09762-7}}</ref> European population rebound from the [[Black Death]] began before the arrival of New World metal, and may have begun a process of inflation that New World silver compounded later in the 16th century.<ref>{{cite book |author=Hackett Fischer, David |title=The Great Wave |publisher=Oxford University Press |year= 1996|page=81 |isbn=0-19-512121-X}}</ref>
From the second half of the 15th century to the first half of the 17th, Western Europe experienced a major inflationary cycle referred to as the "[[price revolution]]",<ref>[[Earl J. Hamilton]], ''American Treasure and the Price Revolution in Spain, 1501–1650'' Harvard Economic Studies, p. 43 (Cambridge, Massachusetts: [[Harvard University Press]], 1934).</ref><ref>{{cite web|url=http://www.chass.utoronto.ca/ecipa/archive/UT-ECIPA-MUNRO-99-02.pdf|archive-url=https://web.archive.org/web/20090306002320/http://www.chass.utoronto.ca/ecipa/archive/UT-ECIPA-MUNRO-99-02.pdf |title=John Munro: ''The Monetary Origins of the 'Price Revolution':South Germany Silver Mining, Merchant Banking, and Venetian Commerce, 1470–1540'', Toronto 2003|archive-date=March 6, 2009}}</ref> with prices on average rising perhaps sixfold over 150 years. This is often attributed to the influx of gold and silver from the [[New World]] into [[Habsburg Spain]],<ref>{{cite book |author=Walton |first=Timothy R. |title=The Spanish Treasure Fleets |publisher=Pineapple Press |year=1994 |isbn=1-56164-049-2 |location=Florida, US |page=85 |language=en-us}}</ref> with wider availability of [[Silver coin|silver]] in previously [[Great Bullion Famine|cash-starved Europe]] causing widespread inflation.<ref>{{Cite journal|url=https://ideas.repec.org/p/bsl/wpaper/2007-12.html|title=The Price Revolution in the 16th Century: Empirical Results from a Structural Vectorautoregression Model|first1=Peter|last1=Bernholz|first2=Peter|last2=Kugler|journal=Working Papers|date=August 1, 2007|via=ideas.repec.org|access-date=March 31, 2015|archive-date=April 25, 2021|archive-url=https://web.archive.org/web/20210425223334/https://ideas.repec.org/p/bsl/wpaper/2007-12.html|url-status=live}}</ref><ref>{{cite book |author=Tracy, James D. |title=Handbook of European History 1400–1600: Late Middle Ages, Renaissance, and Reformation |publisher=Brill Academic Publishers |location=Boston |year= 1994|page=655 |isbn=90-04-09762-7}}</ref> European population rebound from the [[Black Death]] began before the arrival of New World metal, and may have begun a process of inflation that New World silver compounded later in the 16th century.<ref>{{cite book |author=Fischer |first=David Hackett |title=The Great Wave |publisher=Oxford University Press |year=1996 |isbn=0-19-512121-X |page=81 |language=en-uk}}</ref>
 
===After 1700===
 
[[File:Federal Funds Rate (effective).svg|thumb|right|upright=1.6|The U.S. effective [[federal funds rate]] charted over fifty years]]
A pattern of intermittent inflation and deflation periods persisted for centuries until the [[Great Depression]] in the 1930s, which was characterized by major deflation. Since the Great Depression, however, there has been a general tendency for prices to rise every year. In the 1970s and early 1980s, annual inflation in most industrialized countries reached two digits (ten percent or more). The double-digit inflation era was of short duration, however, inflation by the mid-1980s returned to more modest levels. Amid this, general trends there have been spectacular high-inflation episodes in individual countries in [[Interwar period|interwar Europe]], towards the end of the [[Nationalist government|Nationalist Chinese government]] in 1948–1949, and later in some Latin American countries, in Israel, and in Zimbabwe. Some of these episodes are considered [[hyperinflation]] periods, normally designating inflation rates that surpass 50 percent monthly.<ref name=parkin/>


== Measures ==
== Measures ==
{{see also|Consumer price index}}
{{see also|List of countries by inflation rate|Consumer price index}}
[[File:Inflation data.webp|thumb|300px|right|[[producer price index|PPI]] is a [[leading indicator]], CPI and PCE [[Latency (engineering)|lag]]<ref>{{cite web | url=https://www.yahoo.com/now/does-producer-price-index-tell-190327824.html | title=What Does the Producer Price Index Tell You? | access-date=October 1, 2022 | archive-date=December 25, 2021 | archive-url=https://web.archive.org/web/20211225183858/https://www.yahoo.com/now/does-producer-price-index-tell-190327824.html | url-status=live }}</ref>
[[File:Inflation data.webp|thumb|upright=1.6|right|[[producer price index|PPI]] is a [[leading indicator]], CPI and PCE [[Latency (engineering)|lag]]<ref>{{cite web | url=https://www.yahoo.com/now/does-producer-price-index-tell-190327824.html | title=What Does the Producer Price Index Tell You? | date=June 3, 2021 | access-date=October 1, 2022 | archive-date=December 25, 2021 | archive-url=https://web.archive.org/web/20211225183858/https://www.yahoo.com/now/does-producer-price-index-tell-190327824.html | url-status=live }}</ref>
{{legend-line|#00A2FF solid 3px|[[producer price index|PPI]]}}
{{legend-line|#00A2FF solid 3px|[[producer price index|PPI]]}}
{{legend-line|#61D836 solid 3px|Core PPI}}
{{legend-line|#61D836 solid 3px|Core PPI}}
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{{legend-line|#FF2600 solid 3px|[[Personal consumption expenditures price index|PCE]]}}
{{legend-line|#FF2600 solid 3px|[[Personal consumption expenditures price index|PCE]]}}
{{legend-line|#D41876 solid 3px|Core PCE}}]]
{{legend-line|#D41876 solid 3px|Core PCE}}]]
Given that there are many possible measures of the price level, there are many possible measures of price inflation. Most frequently, the term "inflation" refers to a rise in a broad price index representing the overall price level for goods and services in the economy. The [[Consumer Price Index]] (CPI), the [[Personal consumption expenditures price index]] (PCEPI) and the [[GDP deflator]] are some examples of broad price indices. However, "inflation" may also be used to describe a rising price level within a narrower set of assets, goods or services within the economy, such as [[commodity|commodities]] (including food, fuel, metals), [[tangible asset]]s (such as real estate), services (such as entertainment and health care), or [[Labour (economics)|labor]]. Although the values of capital assets are often casually said to "inflate," this should not be confused with inflation as a defined term; a more accurate description for an increase in the value of a capital asset is appreciation. The FBI (CCI), the [[Producer Price Index]], and [[Employment Cost Index]] (ECI) are examples of narrow price indices used to measure price inflation in particular sectors of the economy. [[Core inflation]] is a measure of inflation for a subset of consumer prices that excludes food and energy prices, which rise and fall more than other prices in the short term. The [[Federal Reserve Board]] pays particular attention to the core inflation rate to get a better estimate of long-term future inflation trends overall.<ref>{{Cite book |last=Kiley |first=Michael J. |title=Estimating the common trend rate of inflation for consumer prices and consumer prices excluding food and energy prices |work=Finance and Economic Discussion Series |publisher=Federal Reserve Board |url=http://www.federalreserve.gov/pubs/feds/2008/200838/200838pap.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.federalreserve.gov/pubs/feds/2008/200838/200838pap.pdf |archive-date=2022-10-09 |url-status=live|access-date= May 13, 2015 }}</ref>
Given that there are many possible measures of the price level, there are many possible measures of price inflation. Most frequently, the term "inflation" refers to a rise in a broad price index representing the overall price level for goods and services in the economy. The [[consumer price index]] (CPI), the [[personal consumption expenditures price index]] (PCEPI) and the [[GDP deflator]] are some examples of broad price indices. However, "inflation" may also be used to describe a rising price level within a narrower set of assets, goods or services within the economy, such as [[commodity|commodities]] (including food, fuel, metals), [[tangible asset]]s (such as real estate), services (such as entertainment and health care), or [[Labour (economics)|labor]]. Although the values of capital assets are often casually said to "inflate," this should not be confused with inflation as a defined term; a more accurate description for an increase in the value of a capital asset is appreciation. The FBI (CCI), the [[producer price index]], and [[employment cost index]] (ECI) are examples of narrow price indices used to measure price inflation in particular sectors of the economy. [[Core inflation]] is a measure of inflation for a subset of consumer prices that excludes food and energy prices, which rise and fall more than other prices in the short term. The [[Federal Reserve Board]] pays particular attention to the core inflation rate to get a better estimate of long-term future inflation trends overall.<ref>{{Cite web|last=Kiley |first=Michael J. |title=Estimating the common trend rate of inflation for consumer prices and consumer prices excluding food and energy prices |series=Finance and Economic Discussion Series |publisher=Federal Reserve Board |date=July 2008|url=http://www.federalreserve.gov/pubs/feds/2008/200838/200838pap.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.federalreserve.gov/pubs/feds/2008/200838/200838pap.pdf |archive-date=2022-10-09 |url-status=live|access-date= May 13, 2015 }}</ref>


The inflation rate is most widely calculated by determining the movement or change in a price index, typically the [[consumer price index]].<ref>''See:''
The inflation rate is most widely calculated by determining the movement or change in a price index, typically the [[consumer price index]].<ref>''See:''
* {{harvnb|Hall|Taylor|1993}};
* {{harvnb|Hall|Taylor|1993}};
* {{harvnb|Blanchard|2000}};
* {{harvnb|Blanchard|2021}};
The consumer price index measures movements in prices of a fixed basket of goods and services purchased by a "typical consumer".</ref>
The consumer price index measures movements in prices of a fixed basket of goods and services purchased by a "typical consumer".</ref>
The inflation rate is the percentage change of a price index over time. The [[Retail Prices Index]] is also a measure of inflation that is commonly used in the United Kingdom. It is broader than the CPI and contains a larger basket of goods and services.


Given the recent high inflation, the RPI is indicative of the experiences of a wide range of household types, particularly low-income households.<ref>{{Cite journal |last1=Carruthers |first1=A. G. |last2=Sellwood |first2=D. J. |last3=Ward |first3=P. W. |title=Recent Developments in the Retail Prices Index |url=https://www.jstor.org/stable/2987492 |journal=Journal of the Royal Statistical Society. Series D (The Statistician) |volume=29 |issue=1 |pages=1–32 |doi=10.2307/2987492 |jstor=2987492 |issn=0039-0526 |access-date=June 9, 2022 |archive-date=June 9, 2022 |archive-url=https://web.archive.org/web/20220609045128/https://www.jstor.org/stable/2987492 |url-status=live }}</ref>
The inflation rate is the percentage change of a price index over time. The [[Retail Prices Index]] is also a measure of inflation that is commonly used in the United Kingdom. It is broader than the CPI and contains a larger basket of goods and services. Inflation is politically driven, and policy can directly influence the trend of inflation.
 
The RPI is indicative of the experiences of a wide range of household types, particularly low-income households.<ref>{{Cite journal |last1=Carruthers |first1=A. G. |last2=Sellwood |first2=D. J. |last3=Ward |first3=P. W. |date=1980 |title=Recent Developments in the Retail Prices Index |journal=Journal of the Royal Statistical Society. Series D (The Statistician) |volume=29 |issue=1 |pages=1–32 |doi=10.2307/2987492 |jstor=2987492 |issn=0039-0526 }}</ref>


To illustrate the method of calculation, in January 2007, the U.S. Consumer Price Index was 202.416, and in January 2008 it was 211.080. The formula for calculating the annual percentage rate inflation in the CPI over the course of the year is: <math>\left(\frac{211.080-202.416}{202.416}\right)\times100\%=4.28\%</math>
To illustrate the method of calculation, in January 2007, the U.S. Consumer Price Index was 202.416, and in January 2008 it was 211.080. The formula for calculating the annual percentage rate inflation in the CPI over the course of the year is: <math>\left(\frac{211.080-202.416}{202.416}\right)\times100\%=4.28\%</math>
The resulting inflation rate for the CPI in this one-year period is 4.28%, meaning the general level of prices for typical U.S. consumers rose by approximately four percent in 2007.<ref>The numbers reported here refer to the US Consumer Price Index for All Urban Consumers, All Items, series CPIAUCNS, from base level 100 in base year 1982. They were downloaded from the FRED database at the [[Federal Reserve Bank of St. Louis]] on August 8, 2008.</ref>
 
The resulting inflation rate for the CPI in this one-year period is 4.28%, meaning the general level of prices for typical U.S. consumers rose by approximately four percent in 2007.<ref>The numbers reported here refer to the US Consumer Price Index for All Urban Consumers, All Items, series CPIAUCNS, from base level 100 in base year 1982. They were downloaded from the FRED database at the [[Federal Reserve Bank of St. Louis]] on August 8, 2008.</ref>


Other widely used price indices for calculating price inflation include the following:
Other widely used price indices for calculating price inflation include the following:
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* '''Historical inflation''' Before collecting consistent econometric data became standard for governments, and for the purpose of comparing absolute, rather than relative standards of living, various economists have calculated imputed inflation figures. Most inflation data before the early 20th century is imputed based on the known costs of goods, rather than compiled at the time. It is also used to adjust for the differences in real standard of living for the presence of technology.
* '''Historical inflation''' Before collecting consistent econometric data became standard for governments, and for the purpose of comparing absolute, rather than relative standards of living, various economists have calculated imputed inflation figures. Most inflation data before the early 20th century is imputed based on the known costs of goods, rather than compiled at the time. It is also used to adjust for the differences in real standard of living for the presence of technology.
* '''[[Asset price inflation]]''' is an undue increase in the prices of real assets, such as real estate.
* '''[[Asset price inflation]]''' is an undue increase in the prices of real assets, such as real estate.
In some cases, the measures are meant to be more humorous or to reflect a single place. This includes:
* The [[Christmas Price Index]], which calculates the cost of the items mentioned in a song, "[[The Twelve Days of Christmas (song)|The Twelve Days of Christmas"]].<ref>{{Cite news |last=Olson |first=Elizabeth |date=December 20, 2007 |title=The '12 Days' Index Shows a Record Increase |url=https://www.nytimes.com/2003/12/25/business/the-12-days-index-shows-a-record-increase-704075.html?n=Top%2FReference%2FTimes+Topics%2FSubjects%2FG%2FGifts |work=[[The New York Times]]}}</ref>
* The [[Big Mac Index]], which compares prices across countries.<ref>{{cite news |date=9 April 1998 |title=Big MacCurrencies |url=https://www.economist.com/finance-and-economics/1998/04/09/big-maccurrencies |url-status=live |archive-url=https://web.archive.org/web/20171227100228/http://www.economist.com/node/159859 |archive-date=27 December 2017 |access-date=27 November 2013 |newspaper=The Economist}}</ref>
* The [[Jollof index]], which calculates the price of food needed to make a [[Jollof rice]], a popular African dish.<ref>{{Cite news |last=Erezi |first=Dennis |date=2022-04-28 |title=Jollof Index, Chicken Republic, inflation and changing food consumption patterns |url=https://guardian.ng/features/jollof-index-chicken-republic-inflation-and-changing-food-consumption-patterns/ |location=Lagos, Nigeria|access-date=2024-05-15 |newspaper=[[The Guardian (Nigeria)|The Guardian]]|language=en-US}}</ref>
* The [[Two Dishes One Soup Index]], which calculates the price of food needed to cook one soup and two other dishes for a small family in Hong Kong.
* The [[Herengracht index]], which calculates the price of housing in a fashionable neighborhood of [[Amsterdam]].<ref>{{Cite journal |last=Eichholtz |first=Piet M. A. |date=1996 |title=A Long Run House Price Index: The Herengracht Index, 1628-1973 |url=http://www.ssrn.com/abstract=598 |journal=SSRN Electronic Journal |language=en |doi=10.2139/ssrn.598 |issn=1556-5068|url-access=subscription }}</ref>
* The [[Lipstick index]], which claimed that when the economy got worse, small luxury sales, such as [[lipstick]], would go up.<ref>{{Cite news |date=23 January 2009 |title=Lip service: What lipstick sales tell you about the economy |url=https://www.economist.com/unknown/2009/01/23/lip-service |access-date=2024-06-10 |newspaper=The Economist |issn=0013-0613}}</ref>


=== Issues in measuring ===
=== Issues in measuring ===
Measuring inflation in an economy requires objective means of differentiating changes in nominal prices on a common set of goods and services, and distinguishing them from those price shifts resulting from changes in value such as volume, quality, or performance. For example, if the price of a can of corn changes from $0.90 to $1.00 over the course of a year, with no change in quality, then this price difference represents inflation. This single price change would not, however, represent general inflation in an overall economy. Overall inflation is measured as the price change of a large "basket" of representative goods and services. This is the purpose of a [[price index]], which is the combined price of a "basket" of many goods and services. The combined price is the sum of the weighted prices of items in the "basket". A weighted price is calculated by multiplying the [[unit price]] of an item by the number of that item the average consumer purchases. Weighted pricing is necessary to measure the effect of individual unit price changes on the economy's overall inflation. The [[consumer price index]], for example, uses data collected by surveying households to determine what proportion of the typical consumer's overall spending is spent on specific goods and services, and weights the average prices of those items accordingly. Those weighted average prices are combined to calculate the overall price. To better relate price changes over time, indexes typically choose a "base year" price and assign it a value of 100. Index prices in subsequent years are then expressed in relation to the base year price.<ref name=Taylor>{{cite book |last=Taylor |first=Timothy |title=Principles of Economics |publisher=Freeload Press |date=2008 |isbn=978-1-930789-05-0}}</ref> While comparing inflation measures for various periods one has to take into consideration the [[Base effect (inflation)|base effect]] as well.


Measuring inflation in an economy requires objective means of differentiating changes in nominal prices on a common set of goods and services, and distinguishing them from those price shifts resulting from changes in value such as volume, quality, or performance. For example, if the price of a can of corn changes from $0.90 to $1.00 over the course of a year, with no change in quality, then this price difference represents inflation. This single price change would not, however, represent general inflation in an overall economy. Overall inflation is measured as the price change of a large "basket" of representative goods and services. This is the purpose of a [[price index]], which is the combined price of a "basket" of many goods and services. The combined price is the sum of the weighted prices of items in the "basket". A weighted price is calculated by multiplying the [[unit price]] of an item by the number of that item the average consumer purchases. Weighted pricing is necessary to measure the effect of individual unit price changes on the economy's overall inflation. The [[Consumer Price Index]], for example, uses data collected by surveying households to determine what proportion of the typical consumer's overall spending is spent on specific goods and services, and weights the average prices of those items accordingly. Those weighted average prices are combined to calculate the overall price. To better relate price changes over time, indexes typically choose a "base year" price and assign it a value of 100. Index prices in subsequent years are then expressed in relation to the base year price.<ref name=Taylor /> While comparing inflation measures for various periods one has to take into consideration the [[Base effect (inflation)|base effect]] as well.
Inflation measures are often modified over time, either for the relative weight of goods in the basket, or in the way in which goods and services from the present are compared with goods and services from the past. Basket weights are updated regularly, usually every year, to adapt to changes in consumer behavior. Sudden changes in consumer behavior can still introduce a weighting bias in inflation measurement. For example, during the COVID-19 pandemic it has been shown that the basket of goods and services was no longer representative of consumption during the crisis, as numerous goods and services could no longer be consumed due to government containment measures ("lock-downs").<ref>{{cite journal |last1=Benchimol |first1=Jonathan |last2=Caspi |first2=Itamar |last3=Levin |first3=Yuval |date=2022 |title=The COVID-19 Inflation Weighting in Israel |journal=The Economists' Voice |volume=19 |issue=1 |pages=5–14 |doi=10.1515/ev-2021-0023 |s2cid=245497122 |doi-access=free |arxiv=2506.09875 }}</ref><ref>{{Cite journal|last=Seiler|first=Pascal|date=2020-09-16|title=Weighting bias and inflation in the time of COVID-19: evidence from Swiss transaction data|journal=[[Swiss Journal of Economics and Statistics]]|volume=156|issue=1|article-number=13|doi=10.1186/s41937-020-00057-7|issn=2235-6282|pmc=7493696|pmid=32959014 |doi-access=free }}</ref>
 
Inflation measures are often modified over time, either for the relative weight of goods in the basket, or in the way in which goods and services from the present are compared with goods and services from the past. Basket weights are updated regularly, usually every year, to adapt to changes in consumer behavior. Sudden changes in consumer behavior can still introduce a weighting bias in inflation measurement. For example, during the COVID-19 pandemic it has been shown that the basket of goods and services was no longer representative of consumption during the crisis, as numerous goods and services could no longer be consumed due to government containment measures ("lock-downs").<ref>{{cite journal |last1=Benchimol |first1=Jonathan |last2=Caspi |first2=Itamar |last3=Levin |first3=Yuval |title=The COVID-19 Inflation Weighting in Israel |url=https://doi.org/10.1515/ev-2021-0023 |journal=The Economists' Voice |volume=19 |issue=1 |pages=5–14 |doi=10.1515/ev-2021-0023 |s2cid=245497122 |access-date=2023-03-22}}</ref><ref>{{Cite journal|last=Seiler|first=Pascal|title=Weighting bias and inflation in the time of COVID-19: evidence from Swiss transaction data|url=https://doi.org/10.1186/s41937-020-00057-7|journal=Swiss Journal of Economics and Statistics|volume=156|issue=1|pages=13|doi=10.1186/s41937-020-00057-7|issn=2235-6282|pmc=7493696|pmid=32959014}}</ref>


Over time, adjustments are also made to the type of goods and services selected to reflect changes in the sorts of goods and services purchased by 'typical consumers'. New products may be introduced, older products disappear, the quality of existing products may change, and consumer preferences can shift. Both the sorts of goods and services which are included in the "basket" and the weighted price used in inflation measures will be changed over time to keep pace with the changing marketplace.{{Citation needed}}  Different segments of the population may naturally consume different "baskets" of goods and services and may even experience different inflation rates. It is argued that companies have put more innovation into bringing down prices for wealthy families than for poor families.<ref>{{cite news |last1=Botella |first1=Elena |title=That "Inflation Inequality" Report Has a Major Problem |url=https://slate.com/business/2019/11/inflation-inequality-not-about-beer-lettuce.html |access-date=11 November 2019 |work=[[Slate (magazine)|Slate]] |archive-date=November 30, 2021 |archive-url=https://web.archive.org/web/20211130071656/https://slate.com/business/2019/11/inflation-inequality-not-about-beer-lettuce.html |url-status=live }}</ref>
Over time, adjustments are also made to the type of goods and services selected to reflect changes in the sorts of goods and services purchased by 'typical consumers'. New products may be introduced, older products disappear, the quality of existing products may change, and consumer preferences can shift. Different segments of the population may naturally consume different "baskets" of goods and services and may even experience different inflation rates. It is argued that companies have put more innovation into bringing down prices for wealthy families than for poor families.<ref>{{cite news |last1=Botella |first1=Elena |title=That "Inflation Inequality" Report Has a Major Problem |url=https://slate.com/business/2019/11/inflation-inequality-not-about-beer-lettuce.html |access-date=11 November 2019 |work=[[Slate (magazine)|Slate]] |date=8 November 2019 |archive-date=November 30, 2021 |archive-url=https://web.archive.org/web/20211130071656/https://slate.com/business/2019/11/inflation-inequality-not-about-beer-lettuce.html |url-status=live }}</ref>


Inflation numbers are often [[seasonally adjusted]] to differentiate expected cyclical cost shifts. For example, home heating costs are expected to rise in colder months, and seasonal adjustments are often used when measuring inflation to compensate for cyclical energy or fuel demand spikes. Inflation numbers may be averaged or otherwise subjected to statistical techniques to remove [[statistical noise]] and [[Volatility (finance)|volatility]] of individual prices.<ref>{{cite journal |last1=Vavra |first1=Joseph |title=Inflation Dynamics and Time-Varying Volatility: New Evidence and an SS Interpretation |url=https://academic.oup.com/qje/article-abstract/129/1/215/1897034 |journal=The Quarterly Journal of Economics |volume=129 |issue=1 |pages=215–258 |doi= 10.1093/qje/qjt027 |access-date=2023-03-22}}</ref><ref>{{Cite journal |last=Arlt |first=Josef |title=The problem of annual inflation rate indicator |url=https://onlinelibrary.wiley.com/doi/full/10.1002/ijfe.2563 |journal=International Journal of Finance & Economics |pages=1–17|doi=10.1002/ijfe.2563 |s2cid=233675877 }}</ref>
Inflation numbers are often [[seasonally adjusted]] to differentiate expected cyclical cost shifts. For example, home heating costs are expected to rise in colder months, and seasonal adjustments are often used when measuring inflation to compensate for cyclical energy or fuel demand spikes. Inflation numbers may be averaged or otherwise subjected to statistical techniques to remove [[statistical noise]] and [[Volatility (finance)|volatility]] of individual prices.<ref>{{cite journal |last1=Vavra |first1=Joseph |date=2014 |title=Inflation Dynamics and Time-Varying Volatility: New Evidence and an SS Interpretation |url=https://academic.oup.com/qje/article-abstract/129/1/215/1897034 |journal=The Quarterly Journal of Economics |volume=129 |issue=1 |pages=215–258 |doi=10.1093/qje/qjt027 |access-date=2023-03-22|url-access=subscription }}</ref><ref>{{Cite journal |last=Arlt |first=Josef |date=11 March 2021 |title=The problem of annual inflation rate indicator |url=https://onlinelibrary.wiley.com/doi/full/10.1002/ijfe.2563 |journal=International Journal of Finance & Economics |volume=28 |issue=3 |pages=2772–2788|doi=10.1002/ijfe.2563 |s2cid=233675877 |url-access=subscription }}</ref>


When looking at inflation, economic institutions may focus only on certain kinds of prices, or ''special indices'', such as the [[core inflation]] index which is used by central banks to formulate [[monetary policy]].<ref>{{Cite web|url=https://www.investopedia.com/terms/c/coreinflation.asp|title=Why Core Inflation is Important|last=Kenton|first=Will|website=Investopedia|language=en|access-date=2020-01-17|archive-date=December 14, 2021|archive-url=https://web.archive.org/web/20211214063705/https://www.investopedia.com/terms/c/coreinflation.asp|url-status=live}}</ref>
When looking at inflation, economic institutions may focus only on certain kinds of prices, or ''special indices'', such as the [[core inflation]] index which is used by central banks to formulate [[monetary policy]].<ref>{{Cite web|url=https://www.investopedia.com/terms/c/coreinflation.asp|title=Why Core Inflation is Important|last=Kenton|first=Will|website=Investopedia|language=en|access-date=2020-01-17|archive-date=December 14, 2021|archive-url=https://web.archive.org/web/20211214063705/https://www.investopedia.com/terms/c/coreinflation.asp|url-status=live}}</ref>


Most inflation indices are calculated from weighted averages of selected price changes. This necessarily introduces distortion, and can lead to legitimate disputes about what the true inflation rate is. This problem can be overcome by including all available price changes in the calculation, and then choosing the [[median]] value.<ref>{{cite web |url=http://www.clevelandfed.org/Research/commentary/1991/1201.pdf |title=Median Price Changes: An Alternative Approach to Measuring Current Monetary Inflation |access-date=May 21, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110515145028/http://www.clevelandfed.org/Research/commentary/1991/1201.pdf |archive-date=May 15, 2011 |df=mdy-all }}</ref> In some other cases, governments may intentionally report false inflation rates; for instance, during the presidency of [[Cristina Kirchner]] (2007–2015) the [[government of Argentina]] was criticised for manipulating economic data, such as inflation and GDP figures, for political gain and to reduce payments on its inflation-indexed debt.<ref>{{cite news |url=https://www.reuters.com/article/us-imf-argentina-idUSBRE91019920130202 |title=IMF reprimands Argentina for inaccurate economic data |newspaper=Reuters |access-date=February 2, 2013 |last1=Wroughton |first1=Lesley |archive-date=August 4, 2021 |archive-url=https://web.archive.org/web/20210804134926/https://www.reuters.com/article/us-imf-argentina-idUSBRE91019920130202 |url-status=live }}</ref><ref>{{cite news |url=https://www.bloomberg.com/news/2013-02-01/argentina-becomes-first-nation-censured-by-imf-on-inflation-data.html |title=Argentina Becomes First Nation Censured by IMF on Economic Data |newspaper=Bloomberg.com |access-date=February 2, 2013 |archive-date=March 10, 2021 |archive-url=https://web.archive.org/web/20210310235820/http://www.bloomberg.com/news/2013-02-01/argentina-becomes-first-nation-censured-by-imf-on-inflation-data.html |url-status=live }}</ref>
Most inflation indices are calculated from weighted averages of selected price changes. This necessarily introduces distortion, and can lead to legitimate disputes about what the true inflation rate is. This problem can be overcome by including all available price changes in the calculation, and then choosing the [[median]] value.<ref>{{cite web |url=http://www.clevelandfed.org/Research/commentary/1991/1201.pdf |title=Median Price Changes: An Alternative Approach to Measuring Current Monetary Inflation |access-date=May 21, 2011 |archive-url=https://web.archive.org/web/20110515145028/http://www.clevelandfed.org/Research/commentary/1991/1201.pdf |archive-date=May 15, 2011 }}</ref> In some other cases, governments may intentionally report false inflation rates; for instance, during the presidency of [[Cristina Kirchner]] (2007–2015) the [[government of Argentina]] was criticised for manipulating economic data, such as inflation and GDP figures, for political gain and to reduce payments on its inflation-indexed debt.<ref>{{cite news |url=https://www.reuters.com/article/us-imf-argentina-idUSBRE91019920130202 |title=IMF reprimands Argentina for inaccurate economic data |newspaper=Reuters |date=February 2, 2013 |access-date=February 2, 2013 |last1=Wroughton |first1=Lesley |archive-date=August 4, 2021 |archive-url=https://web.archive.org/web/20210804134926/https://www.reuters.com/article/us-imf-argentina-idUSBRE91019920130202 |url-status=live }}</ref><ref>{{cite news |url=https://www.bloomberg.com/news/2013-02-01/argentina-becomes-first-nation-censured-by-imf-on-inflation-data.html |title=Argentina Becomes First Nation Censured by IMF on Economic Data |newspaper=Bloomberg.com |date=February 2, 2013 |access-date=February 2, 2013 |archive-date=March 10, 2021 |archive-url=https://web.archive.org/web/20210310235820/http://www.bloomberg.com/news/2013-02-01/argentina-becomes-first-nation-censured-by-imf-on-inflation-data.html |url-status=live }}</ref>


===Inflation expectations===
===Official vs. true vs. perceived inflation===
The true inflation is one percentage point lower than the official one, according to research. Therefore, the 2% inflation target is needed to prevent the true inflation being close to zero or even deflation. The reasons are the following:<ref>{{cite web|url=https://cals.ncsu.edu/news/you-decide-why-stop-at-an-inflation-rate-of-2/|title=You Decide: Why Stop at an Inflation Rate Target of 2%?|date=January 29, 2023|website=CALS News|publisher=NC State University}}</ref>
* '''Substitution effect''': People buy fewer products with the highest price rises and more of those whose prices have risen less. Therefore, the price of their non-fixed shopping basket rises less than that of a fixed shopping basket.
* '''Unobserved quality improvements''': Even though statisticians try to take quality improvements into account, they are not able to do it fully. This is why people rather buy current products at the higher prices than old products at their old prices.
* '''New goods''': The current shopping basket is much better, because it has goods that you previously could not even dream of.<ref>{{cite web|url=https://www.dummies.com/article/business-careers-money/business/economics/inflation-usually-overestimated-228118/|title=Why Inflation Is Usually Overestimated|author=Dan Richards|author2=Manzur Rashid|author3=Peter Antonioni|date=November 1, 2016|publisher=John Wiley & Sons}}</ref>


Inflation expectations or expected inflation is the rate of inflation that is anticipated for some time in the foreseeable future. There are two major approaches to modeling the formation of inflation expectations. [[Adaptive expectations]] models them as a weighted average of what was expected one period earlier and the actual rate of inflation that most recently occurred. [[Rational expectations]] models them as unbiased, in the sense that the expected inflation rate is not systematically above or systematically below the inflation rate that actually occurs.
Nevertheless, people overestimate the inflation even vs. the measured inflation. This is because they focus more on commonly-bought items than on durable goods, and more on price increases than on price decreases.<ref name=StatisticsCanada>{{cite web|date=January 19, 2022 |publisher=Statistics Canada |title=The naked eye versus the CPI: How does our perception of inflation stack up against the data? |url=https://www.statcan.gc.ca/o1/en/plus/256-naked-eye-versus-cpi-how-does-our-perception-inflation-stack-against-data}}<!-- auto-translated from Finnish by Module:CS1 translator --></ref> On the other hand, different people have different shopping baskets and hence face different inflation rates.<ref name=StatisticsCanada/>


A long-standing survey of inflation expectations is the University of Michigan survey.<ref>{{cite web|url=https://fred.stlouisfed.org/series/MICH|title=University of Michigan: Inflation Expectation|publisher=Economic Research, Federal Reserve Bank of St. Louis|access-date=March 9, 2017|archive-date=November 7, 2021|archive-url=https://web.archive.org/web/20211107075130/https://fred.stlouisfed.org/series/MICH|url-status=live}}</ref>
[[File:Consumer price index 2024 relative to 2010.svg|thumb|upright=1.5|[[Consumer price index by country]] in % (2024, relative to 2010)<ref name="World Bank CPI">{{Cite web|url=https://data.worldbank.org/indicator/FP.CPI.TOTL?end=2024&name_desc=false&start=1960&view=chart&year=2024|title=Consumer price index (2010=100), World Bank Group, accessed July 2025}}</ref>
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[[Cumulative process|Cumulative]] inflation due to the [[compound interest|compound effect]] can impact the perception of inflation.<ref name="n873">{{cite journal | last1=McGranahan | first1=Leslie | last2=Paulson | first2=Anna L. | title=The Incidence of Inflation: Inflation Experiences by Demographic Group: 1981-2004 | journal=FRB of Chicago Working Paper | date=2005 | ssrn=3887185 | url=https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3887185 | access-date=23 April 2025}}</ref>


Inflation expectations affect the economy in several ways. They are more or less built into [[nominal interest rate]]s, so that a rise (or fall) in the expected inflation rate will typically result in a rise (or fall) in nominal interest rates, giving a smaller effect if any on [[real interest rate]]s. In addition, higher expected inflation tends to be built into the rate of wage increases, giving a smaller effect if any on the changes in [[real wages]]. Moreover, the response of inflationary expectations to monetary policy can influence the division of the effects of policy between inflation and unemployment (see [[Monetary policy credibility]]).
===Inflation expectations===
Inflation expectations or expected inflation is the rate of inflation that is anticipated for some time in the foreseeable future. There are two major approaches to modeling the formation of inflation expectations. [[Adaptive expectations]] models them as a weighted average of what was expected one period earlier and the actual rate of inflation that most recently occurred. [[Rational expectations]] models them as unbiased, in the sense that the expected inflation rate is not systematically above or systematically below the inflation rate that actually occurs.


== Causes ==
A long-standing survey of inflation expectations is the University of Michigan survey.<ref>{{cite web|url=https://fred.stlouisfed.org/series/MICH|title=University of Michigan: Inflation Expectation|date=January 1978|publisher=Economic Research, Federal Reserve Bank of St. Louis|access-date=March 9, 2017|archive-date=November 7, 2021|archive-url=https://web.archive.org/web/20211107075130/https://fred.stlouisfed.org/series/MICH|url-status=live}}</ref>


Historically, a great deal of economic literature was concerned with the question of what causes inflation and what effect it has. There were different schools of thought as to the causes of inflation; most historical theories can be divided into two broad areas: ''quality'' theories of inflation and ''quantity'' theories of inflation. The quality theory of inflation rests on the expectation of a seller accepting currency to be able to exchange that currency at a later time for goods they desire as a buyer.
Inflation expectations affect the economy in several ways. They are more or less built into [[nominal interest rate]]s, so that a rise (or fall) in the expected inflation rate will typically result in a rise (or fall) in nominal interest rates, giving a smaller effect if any on [[real interest rate]]s. In addition, higher expected inflation tends to be built into the rate of wage increases, giving a smaller effect if any on the changes in [[real wages]]. Moreover, the response of inflationary expectations to monetary policy can influence the division of the effects of policy between inflation and unemployment (see [[monetary policy credibility]]).


In the late twentieth century, there was broad agreement among economists that in the long run, the inflation rate depends on the growth rate of the money supply relative to the growth of real income. This view, called the [[quantity theory of money]], was accepted as an accurate explanation of inflation in the long run. Consequently, however, in the short and medium term inflation may be affected by supply and demand pressures in the economy, and influenced by the relative elasticity of wages, prices and interest rates.<ref name="federalreserve2004">{{Cite web|url=https://www.ecb.europa.eu/press/pressconf/2004/html/is040701.en.html|archive-url=https://web.archive.org/web/20150812054831/http://www.federalreserve.gov/boarddocs/hh/2004/july/testimony.htm |url-status=dead |title=Introductory statement to the press conference|archive-date=August 12, 2015|website=European Central Bank}}</ref>
==Causes==
{{Organize section|date=February 2024}}
===Historical approaches===
Theories of the origin and causes of inflation have existed since at least the 16th century. Two competing theories, the [[quantity theory of money]] and the [[real bills doctrine]], appeared in various guises during century-long debates on recommended central bank behaviour. In the 20th century, [[Keynesian]], [[monetarist]] and [[New classical macroeconomics|new classical]] (also known as [[rational expectations]]) views on inflation dominated post-World War II [[macroeconomics]] discussions, which were often heated intellectual debates, until some kind of synthesis of the various theories was reached by the end of the century.


The question of whether the short-term effects last long enough to be important is the central topic of debate between monetarist and Keynesian economists. In [[monetarism]] prices and wages adjust quickly enough to make other factors merely marginal behavior on a general trend-line. In the [[Keynesian economics|Keynesian]] view, interest rates, prices, and wages adjust at different rates, and these differences have enough effects on real output to be "long term" in the view of people in an economy.
====Before 1936====
{{main|Real bills doctrine}}
The [[price revolution]] from ca. 1550–1700 caused several thinkers to present what is now considered to be early formulations of the [[quantity theory of money]] (QTM). Other contemporary authors attributed rising price levels to the debasement of national coinages. Later research has shown that also growing output of [[Central Europe]]an silver mines and an increase in the [[velocity of money]] because of innovations in the payment technology, in particular the increased use of [[bill of exchange|bills of exchange]], contributed to the price revolution.<ref name=Dimand>{{cite book|last1=Dimand |first1=Robert W. |chapter=Monetary Economics, History of |title=The New Palgrave Dictionary of Economics |date=2016 |pages=1–13 |doi=10.1057/978-1-349-95121-5_2721-1 |chapter-url=https://link.springer.com/referenceworkentry/10.1057/978-1-349-95121-5_2721-1 |publisher=Palgrave Macmillan UK |isbn=978-1-349-95121-5 |language=en}}</ref>


=== Keynesian view ===
An alternative theory, the [[real bills doctrine]] (RBD), originated in the 17th and 18th century, receiving its first authoritative exposition in [[Adam Smith]]'s ''[[The Wealth of Nations]]''.<ref>{{cite journal |last1=Green |first1=Roy |title=Real Bills Doctrine |journal=The New Palgrave Dictionary of Economics |date=2018 |pages=11328–11330 |doi=10.1057/978-1-349-95189-5_1614|isbn=978-1-349-95188-8 }}</ref> It asserts that banks should issue their money in exchange for short-term real bills of adequate value. As long as banks only issue a dollar in exchange for assets worth at least a dollar, the issuing bank's assets will naturally move in step with its issuance of money, and the money will hold its value. Should the bank fail to get or maintain assets of adequate value, then the bank's money will lose value, just as any financial security will lose value if its asset backing diminishes. The real bills doctrine (also known as the backing theory) thus asserts that inflation results when money outruns its issuer's assets. The quantity theory of money, in contrast, claims that inflation results when money outruns the economy's production of goods.
{{see|Keynesian Revolution}}
{{see|Keynes's theory of wages and prices}}
[[Keynesian economics]] proposes that changes in the money supply do not directly affect prices in the short run, and that visible inflation is the result of demand pressures in the economy expressing themselves in prices.


There are three major sources of inflation, as part of what [[Robert J. Gordon]] calls the "[[triangle model]]":<ref>Robert J. Gordon (1988), ''Macroeconomics: Theory and Policy'', 2nd ed., Chap. 22.4, 'Modern theories of inflation'. McGraw-Hill.</ref>
During the 19th century, three different schools debated these questions: The [[British Currency School]] upheld a quantity theory view, believing that the [[Bank of England]]'s issues of bank notes should vary one-for-one with the bank's gold reserves. In contrast to this, the [[British Banking School]] followed the real bills doctrine, recommending that the bank's operations should be governed by the needs of trade: Banks should be able to issue currency against bills of trading, i.e. "real bills" that they buy from merchants. A third group, the Free Banking School, held that competitive private banks would not overissue, even though a monopolist central bank could be believed to do it.<ref>{{cite journal |last1=Schwartz |first1=Anna J. |title=Banking School, Currency School, Free Banking School |journal=The New Palgrave Dictionary of Economics |date=2018 |pages=694–700 |doi=10.1057/978-1-349-95189-5_263|isbn=978-1-349-95188-8 }}</ref>
* ''[[Demand-pull inflation]]'' is caused by increases in aggregate demand due to increased private and government spending,<ref name="Biden Is Clueless About Inflation – Reason – Nick Gillespie & Regan Taylor reporting">{{cite web |last1=Gillespie |first1=Nick |last2=Taylor |first2=Regan |title=Biden Is Clueless About Inflation |url=https://reason.com/video/2022/04/01/biden-is-clueless-about-inflation/ |website=reason.com |publisher=Reason |access-date=4 April 2022 |archive-date=April 27, 2022 |archive-url=https://web.archive.org/web/20220427225435/https://reason.com/video/2022/04/01/biden-is-clueless-about-inflation/ |url-status=live }}</ref><ref name="Blame Insane Government Spending for Inflation – Reason – Veronique De Rugy">{{cite web |last1=De Rugy |first1=Veronique |title=Blame Insane Government Spending for Inflation |url=https://reason.com/2022/03/31/blame-insane-government-spending-for-inflation/ |website=reason.com |publisher=Reason |access-date=4 April 2022 |archive-date=May 11, 2022 |archive-url=https://web.archive.org/web/20220511170305/https://reason.com/2022/03/31/blame-insane-government-spending-for-inflation/ |url-status=live }}</ref> etc. Demand inflation encourages economic growth since the excess demand and favourable market conditions will stimulate investment and expansion.
* ''[[Cost-push inflation]]'', also called "supply shock inflation," is caused by a drop in aggregate supply (potential output). This may be due to natural disasters, war or increased prices of inputs. For example, a sudden decrease in the supply of oil, leading to increased oil prices, can cause cost-push inflation. Producers for whom oil is a part of their costs could then pass this on to consumers in the form of increased prices. Another example stems from unexpectedly high insured losses, either legitimate (catastrophes) or fraudulent (which might be particularly prevalent in times of recession). High inflation can prompt employees to demand rapid wage increases, to keep up with consumer prices. In the cost-push theory of inflation, rising wages in turn can help fuel inflation. In the case of collective bargaining, wage growth will be set as a function of inflationary expectations, which will be higher when inflation is high. This can cause a [[price/wage spiral|wage spiral]].<ref>{{cite web|url=https://www.britannica.com/EBchecked/topic/287700/inflation/3512/The-cost-push-theory|title=Encyclopædia Britannica|access-date=September 13, 2014|archive-date=September 7, 2014|archive-url=https://web.archive.org/web/20140907030214/http://www.britannica.com/EBchecked/topic/287700/inflation/3512/The-cost-push-theory/|url-status=live}}</ref> In a sense, inflation begets further inflationary expectations, which beget further inflation.
* [[Built-in inflation]] is induced by [[adaptive expectations]], and is often linked to the "[[price/wage spiral]]". It involves workers trying to keep their wages up with prices (above the rate of inflation), and firms passing these higher labor costs on to their customers as higher prices, leading to a feedback loop. Built-in inflation reflects events in the past, and so might be seen as [[hangover inflation]].


[[Demand-pull theory]] states that inflation accelerates when [[aggregate demand]] increases beyond the ability of the economy to produce (its [[potential output]]). Hence, any factor that increases aggregate demand can cause inflation.<ref>{{cite book |last1=O'Sullivan |first1=Arthur |author-link1=Arthur O'Sullivan (economist) |last2=Sheffrin |first2=Steven M. |title=Economics: Principles in Action  |edition=2nd |series=The Wall Street Journal:Classroom Edition |year=2003 |orig-year= 2002|publisher= Pearson Prentice Hall: Addison Wesley Longman|location=Upper Saddle River, New Jersey |isbn=0-13-063085-3 |page= 341}}</ref> However, in the long run, aggregate demand can be held above productive capacity only by increasing the quantity of money in circulation faster than the real growth rate of the economy. Another (although much less common) cause can be a rapid decline in the ''demand'' for money, as happened in Europe during the [[Black Death]], or in the [[Greater East Asia Co-Prosperity Sphere|Japanese occupied territories]] just before the defeat of Japan in 1945.
The debate between currency, or quantity theory, and banking schools during the 19th century prefigures current questions about the credibility of money in the present. In the 19th century, the banking schools had greater influence in policy in the United States and Great Britain, while the [[British Currency School|currency schools]] had more influence "on the continent", that is in non-British countries, particularly in the [[Latin Monetary Union]] and the [[Scandinavian Monetary Union]].


The effect of money on inflation is most obvious when governments finance spending in a crisis, such as a civil war, by printing money excessively. This sometimes leads to [[hyperinflation]], a condition where prices can double in a month or even daily.<ref>{{cite web |last1=Hanke |first1=Steve H.|language=en |title=World Hyperinflations |url=https://www.cato.org/sites/cato.org/files/pubs/pdf/hanke-krus-hyperinflation-table-may-2013.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.cato.org/sites/cato.org/files/pubs/pdf/hanke-krus-hyperinflation-table-may-2013.pdf |archive-date=2022-10-09 |url-status=live }}</ref> The money supply is also thought to play a major role in determining moderate levels of inflation, although there are differences of opinion on how important it is. For example, [[Monetarism|monetarist]] economists believe that the link is very strong; Keynesian economists, by contrast, typically emphasize the role of [[aggregate demand]] in the economy rather than the money supply in determining inflation. That is, for Keynesians, the money supply is only one determinant of aggregate demand.
During the Bullionist Controversy during the [[Napoleonic Wars]], [[David Ricardo]] argued that the Bank of England had engaged in over-issue of bank notes, leading to commodity price increases. In the late 19th century, supporters of the quantity theory of money led by [[Irving Fisher]] debated with supporters of [[bimetallism]]. Later, [[Knut Wicksell]] sought to explain price movements as the result of real shocks rather than movements in money supply, resounding statements from the real bills doctrine.<ref name=Dimand/>


Some Keynesian economists also disagree with the notion that central banks fully control the money supply, arguing that central banks have little control, since the money supply adapts to the demand for bank credit issued by commercial banks. This is known as the theory of [[endogenous money]], and has been advocated strongly by [[post-Keynesian]]s as far back as the 1960s. This position is not universally accepted{{snd}}banks create money by making loans, but the aggregate volume of these loans diminishes as real interest rates increase. Thus, central banks can influence the money supply by making money cheaper or more expensive, thus increasing or decreasing its production.
In 2019, monetary historians [[Thomas M. Humphrey]] and [[Richard Timberlake]] published "Gold, the Real Bills Doctrine, and the Fed: Sources of Monetary Disorder 1922–1938".<ref>{{cite book |last1=Humphrey |first1=Thomas M. |last2=Timberlake |first2=Richard H. |title=Gold, the Real Bills Doctrine, and the Fed: sources of monetary disorder 1922–1938 |date=2019 |publisher=Cato Institute |location=Washington, D.C. |isbn=978-1-948647-13-7 |edition=First}}</ref>


A fundamental concept in inflation analysis is the relationship between inflation and unemployment, called the [[Phillips curve]]. This model suggests that there is a [[trade-off]] between [[price stability]] and employment. Therefore, some level of inflation could be considered desirable to minimize unemployment. The Phillips curve model described the U.S. experience well in the 1960s but failed to describe the [[1973–75 recession|stagflation experienced in the 1970s]]. Thus, modern [[macroeconomics]] describes inflation using a Phillips curve that is able to shift due to such matters as supply shocks and structural inflation. The former refers to such events like the [[1973 oil crisis]], while the latter refers to the [[price/wage spiral]] and [[Adaptive expectations|inflationary expectations]] implying that inflation is the new normal. Thus, the Phillips curve represents only the demand-pull component of the triangle model.
====Keynes and the early Keynesians====
{{further|Keynesian Revolution}}
{{further|Keynes's theory of wages and prices}}
John Maynard Keynes in his 1936 main work ''[[The General Theory of Employment, Interest and Money]]'' emphasized that wages and prices were [[Nominal rigidity|sticky]] in the short run, but gradually responded to [[aggregate demand]] shocks. These could arise from many different sources, e.g. autonomous movements in investment or fluctuations in private wealth or interest rates.<ref name=parkin/> Economic policy could also affect demand, [[monetary policy]] by affecting interest rates and [[fiscal policy]] either directly through the level of [[government final consumption expenditure]] or indirectly by changing [[Disposable and discretionary income|disposable income]] via tax changes.


Another concept of note is the [[potential output]] (sometimes called the "natural gross domestic product"), a level of GDP, where the economy is at its optimal level of production given institutional and natural constraints. (This level of output corresponds to the Non-Accelerating Inflation Rate of Unemployment, [[NAIRU]], or the "natural" rate of [[unemployment]] or the full-employment unemployment rate.) If GDP exceeds its potential (and unemployment is below the NAIRU), the theory says that inflation will ''accelerate'' as suppliers increase their prices and built-in inflation worsens. If GDP falls below its potential level (and unemployment is above the NAIRU), inflation will ''decelerate'' as suppliers attempt to fill excess capacity, cutting prices and undermining built-in inflation.<ref>{{cite journal | last = Coe | first = David T. | title = Nominal Wages. The NAIRU and Wage Flexibility | publisher = Organisation for Economic Co-operation and Development (OECD) | url = http://www.oecd.org/dataoecd/59/19/33917832.pdf | year = 1985 | id = MPRA Paper 114295 | journal = OECD Economic Studies | issue = 5 | pages = 87–126 | s2cid = 18879396 | access-date = February 24, 2010 | archive-date = February 26, 2018 | archive-url = https://web.archive.org/web/20180226211933/http://www.oecd.org/dataoecd/59/19/33917832.pdf | url-status = live }}</ref>
The various sources of variations in aggregate demand will cause cycles in both output and price levels. Initially, a demand change will primarily affect output because of the price stickiness, but eventually prices and wages will adjust to reflect the change in demand. Consequently, movements in real output and prices will be positively, but not strongly, correlated.<ref name=parkin/>


However, one problem with this theory for policy-making purposes is that the exact level of potential output (and of the NAIRU) is generally unknown and tends to change over time. Inflation also seems to act in an asymmetric way, rising more quickly than it falls. It can change because of policy: for example, high unemployment under British Prime Minister [[Margaret Thatcher]] might have led to a rise in the NAIRU (and a fall in potential) because many of the unemployed found themselves as [[Structural unemployment|structurally unemployed]], unable to find jobs that fit their skills. A rise in structural unemployment implies that a smaller percentage of the labor force can find jobs at the NAIRU, where the economy avoids crossing the threshold into the realm of accelerating inflation.
Keynes' propositions formed the basis of [[Keynesian economics]] which came to dominate macroeconomic research and economic policy in the first decades after World War II.<ref name=Blanchard/>{{rp|526}} Other Keynesian economists developed and reformed several of Keynes' ideas. Importantly, [[William Phillips (economist)|Alban William Phillips]] in 1958 published indirect evidence of a negative relation between inflation and unemployment, confirming the Keynesian emphasis on a positive correlation between increases in real output (normally accompanied by a fall in unemployment) and rising prices, i.e. inflation. Phillips' findings were confirmed by other empirical analyses and became known as a [[Phillips curve]]. It quickly became central to macroeconomic thinking, apparently offering a stable trade-off between [[price stability]] and employment. The curve was interpreted to imply that a country could achieve low unemployment if it were willing to tolerate a higher inflation rate or vice versa.<ref name=Blanchard/>{{rp|173}}


==== Unemployment ====
The Phillips curve model described the U.S. experience well in the 1960s but failed to describe the [[1973–75 recession|stagflation experienced in the 1970s]].


A connection between inflation and unemployment has been drawn since the emergence of large scale unemployment in the 19th century, and connections continue to be drawn today. However, the [[unemployment rate]] generally only affects inflation in the short-term but not the long-term.<ref name=chang>Chang, R. (1997) [https://www.frbatlanta.org/filelegacydocs/ACFC7.pdf "Is Low Unemployment Inflationary?"] {{webarchive|url=https://web.archive.org/web/20131113212953/https://www.frbatlanta.org/filelegacydocs/ACFC7.pdf }} ''Federal Reserve Bank of Atlanta Economic Review'' 1Q97:4–13</ref> In the long term, the [[velocity of money]] is far more predictive of inflation than low unemployment.<ref name=hossfeld>Oliver Hossfeld (2010) [http://www.hhl.de/fileadmin/texte/publikationen/forschungspapiere/HOSSFELD_USMONEY_INFERWP_2010-4.pdf "US Money Demand, Monetary Overhang, and Inflation Prediction"] {{Webarchive|url=https://web.archive.org/web/20131113215511/http://www.hhl.de/fileadmin/texte/publikationen/forschungspapiere/HOSSFELD_USMONEY_INFERWP_2010-4.pdf }} ''International Network for Economic Research'' working paper no. 2010.4</ref>
==== Monetarism ====
 
[[File:CPI 1914-2022.webp|thumb|alt=CPI 1914–2022|upright=1.6|
In [[Marxian economics]], the unemployed serve as a [[reserve army of labor]], which restrain wage inflation. In the 20th century, similar concepts in Keynesian economics include the [[NAIRU]] (Non-Accelerating Inflation Rate of Unemployment) and the [[Phillips curve]].
 
==== Profiteering under consolidation ====
 
[[File:USprofitsVsCPIchange.png|thumb|U.S. corporate profits as a proportion of GDP (blue) and year-over-year change in the Consumer Price Index (red) 2017-2022]]
 
Keynesian price inelasticity can contribute to inflation when [[Consolidation (business)|firms consolidate]], tending to support [[monopoly]] or [[monopsony]] conditions anywhere along the [[supply chain]] for goods or services. When this occurs, firms can provide greater [[shareholder value]] by taking a larger proportion of [[Profit (accounting)|profits]] than by investing in providing greater volumes of their outputs.<ref name="Mankiw7partV">{{cite book |last1=Mankiw |first1=N. Gregory |title=Principles of economics |location=Stamford, CT |isbn=978-1285165875 |pages=257–367 |edition=Seventh |chapter=Part V, chapters 13-17}}</ref><ref name="BivinsEpi22">{{cite web |last1=Bivins |first1=Josh |title=Corporate profits have contributed disproportionately to inflation. How should policymakers respond? |url=https://www.epi.org/blog/corporate-profits-have-contributed-disproportionately-to-inflation-how-should-policymakers-respond/ |website=Economic Policy Institute |access-date=25 May 2022 |archive-date=May 25, 2022 |archive-url=https://web.archive.org/web/20220525111507/https://www.epi.org/blog/corporate-profits-have-contributed-disproportionately-to-inflation-how-should-policymakers-respond/ |url-status=live }}</ref>
 
[[File:OilVsGasoline1Q22.png|thumb|US prices of crude oil and gasoline in February and March, 2022]]
 
Examples include the rise in gasoline and other fossil fuel prices in the first quarter of 2022. Shortly after initial energy price shocks caused by the [[2022 Russian invasion of Ukraine]] subsided, oil companies found that supply chain constrictions, already exacerbated by the ongoing global [[COVID-19 pandemic]], supported price inelasticity, i.e., they began lowering prices to match the [[price of oil]] when it fell much more slowly than they had increased their prices when costs rose.<ref>{{cite news |last1=Cronin |first1=Brittany |title=The good times are rolling for Big Oil. 3 things to know about their surging profits |url=https://www.npr.org/2022/05/07/1097177459/big-oil-exxon-earnings-gasoline-prices-crude |access-date=25 May 2022 |work=NPR |language=en |archive-date=May 21, 2022 |archive-url=https://web.archive.org/web/20220521123900/https://www.npr.org/2022/05/07/1097177459/big-oil-exxon-earnings-gasoline-prices-crude |url-status=live }}</ref> California's five largest gasoline companies, [[Chevron Corporation]], [[Marathon Petroleum]], [[Valero Energy]], [[PBF Energy]], and [[Phillips 66]], responsible for 96% of transportation fuel sold in the state, all participated in this behavior, reaping first quarter profits much larger than any of their quarterly results in the previous several years.<ref>{{cite news |last1=Elias |first1=Thomas |title=All doubt has been removed, oil companies are gouging us |work=Pennensula News |issue=150 |publisher=Bay Area News Group |page=6 |url=https://napavalleyregister.com/opinion/columnists/thomas-d-elias-doubt-removed-oil-refiners-gouging-us/article_365dae0c-d7c3-11ec-948e-bfc2c65051fe.html |access-date=May 25, 2022 |archive-date=May 26, 2022 |archive-url=https://web.archive.org/web/20220526145052/https://napavalleyregister.com/opinion/columnists/thomas-d-elias-doubt-removed-oil-refiners-gouging-us/article_365dae0c-d7c3-11ec-948e-bfc2c65051fe.html |url-status=live }}</ref> On May 19, 2022, the U.S. House of Representatives passed a bill to prevent such "[[price gouging]]" by addressing the resulting [[windfall profits]], but it is unlikely to prevail against the minority filibuster challenge in the Senate.<ref>{{cite news |last1=Matthew |first1=Daly |title=House approves bill to combat gasoline 'price gouging' |url=https://www.pbs.org/newshour/amp/economy/house-approves-bill-to-combat-gasoline-price-gouging |access-date=25 May 2022 |work=PBS NewsHour |agency=Associated Press |language=en |archive-date=May 21, 2022 |archive-url=https://web.archive.org/web/20220521194012/https://www.pbs.org/newshour/amp/economy/house-approves-bill-to-combat-gasoline-price-gouging |url-status=live }}</ref>
 
Similarly in the first quarter of 2022, meatpacking giant [[Tyson Foods]] relied on downward price inelasticity in packaged chicken and related products to increase their profits to about $500 million, responding to a $1.5 billion increase in their costs with almost $2 billion in price hikes. Tyson's three main competitors, having essentially no ability to compete on lower prices because supply chain constriction would not support an increase in volumes, followed suit. Tyson's quarter was one of their most profitable, expanding their [[operating margin]] 38%.<ref>{{cite news |last1=Gardner |first1=Eric |title=There's a Price Gouging Smoking Gun In Tyson's Earnings Report |url=https://perfectunion.us/tyson-foods-price-gouging/ |access-date=25 May 2022 |work=More Perfect Union |language=en |archive-date=May 19, 2022 |archive-url=https://web.archive.org/web/20220519165351/https://perfectunion.us/tyson-foods-price-gouging/ |url-status=live }}</ref> [[UBS#Global Wealth Management|UBS Global Wealth Management]] chief economist [[Paul Donovan (economist)|Paul Donovan]] said this has happened because post-pandemic household balance sheets have kept [[consumer spending]] demand strong enough to encourage producers to raise prices faster than costs, and because consumers have been gullible enough to find exaggerated narratives justifying such price hikes plausible.<ref>{{cite news |last1=Donovan |first1=Paul |title=Fed should make clear that rising profit margins are spurring inflation |url=https://www.ft.com/content/837c3863-fc15-476c-841d-340c623565ae |access-date=12 February 2023 |work=Financial Times }}</ref>
 
==== Effect of economic growth ====
 
If economic growth matches the growth of the money supply, inflation should not occur when all else is equal.<ref>{{Cite journal |first= Miguel |last= Sigrauski |title= Inflation and Economic Growth |journal= Journal of Political Economy |year= 1961|volume= 75 |issue= 6 |pages= 796–810 |doi= 10.1086/259360|citeseerx= 10.1.1.330.9556 |s2cid= 153472492 }}</ref> A large variety of factors can affect the rate of both. For example, investment in market production, infrastructure, education, and [[preventive health care]] can all grow an economy in greater amounts than the investment spending.<ref>{{Cite journal |first= David R. |last= Henderson |year= 1999 |title= Does Growth Cause Inflation? |url= https://www.cato.org/policy-report/novemberdecember-1999/does-growth-cause-inflation |journal= Cato Policy Report |volume= 21 |access-date= May 22, 2017 |archive-date= December 26, 2020 |archive-url= https://web.archive.org/web/20201226042437/https://www.cato.org/policy-report/novemberdecember-1999/does-growth-cause-inflation |url-status= live }}</ref><ref>{{cite news|url=https://www.nytimes.com/interactive/2011/01/02/business/20110102-metrics-graphic.html?_r=0|title=In Investing, It's When You Start And When You Finish|newspaper=New York Times|access-date=August 22, 2017|archive-date=October 17, 2017|archive-url=https://web.archive.org/web/20171017114954/http://www.nytimes.com/interactive/2011/01/02/business/20110102-metrics-graphic.html?_r=0|url-status=live}}</ref>
 
=== Monetarist view ===
[[File:CPI 1914-2022.webp|thumb|alt=CPI 1914-2022|261px|
{{legend|#0076BA |Inflation}}
{{legend|#0076BA |Inflation}}
{{legend|#EE220C |[[Deflation]]}}
{{legend|#EE220C |[[Deflation]]}}
{{legend-line|#1DB100 solid 3px|[[Money supply|M2 money supply]] increases Year/Year}}
{{legend-line|#1DB100 solid 3px|[[Money supply|M2 money supply]] increases Year/Year}}
]]
]]
[[File:M2 and Inflation USA.svg|thumb|right|Inflation and the growth of money supply (M2)]]
[[File:M2 and Inflation USA.svg|thumb|right|upright=1.6|Inflation and the growth of money supply (M2)]]
{{Further|Monetarism}}
{{Further|Monetarism}}


Monetarists believe the most significant factor influencing inflation or deflation is how fast the money supply grows or shrinks. They consider fiscal policy, or government spending and taxation, as ineffective in controlling inflation.<ref>{{cite book |author=Lagassé, Paul |title=The Columbia Encyclopedia |publisher=Columbia University Press |location=New York |year=2000 |chapter=Monetarism |isbn=0-7876-5015-3 |edition=6th |url-access=registration |url=https://archive.org/details/columbiaencyclop00laga }}</ref> The monetarist economist [[Milton Friedman]] famously stated, ''"Inflation is always and everywhere a monetary phenomenon."''<ref>{{cite book|first1=Milton|last1= Friedman|first2=Anna Jacobson |last2=Schwartz|title=A Monetary History of the United States, 1867–1960|url=https://archive.org/details/monetaryhistoryo00frie|url-access=registration|year=1963|publisher=Princeton University Press}}</ref>
During the 1960s the Keynesian view of inflation and macroeconomic policy altogether were challenged by [[Monetarism|monetarist]] theories, led by [[Milton Friedman]].<ref name=Blanchard/>{{rp|528–529}} Friedman famously stated that:<blockquote>''Inflation is always and everywhere a monetary phenomenon.''<ref>{{cite book|first1=Milton|last1= Friedman|first2=Anna Jacobson |last2=Schwartz|title=A Monetary History of the United States, 1867–1960|url=https://archive.org/details/monetaryhistoryo00frie|url-access=registration|year=1963|publisher=Princeton University Press}}</ref></blockquote>He revived the [[quantity theory of money]] by [[Irving Fisher]] and others, making it into a central tenet of monetarist thinking, arguing that the most significant factor influencing inflation or deflation is how fast the [[money supply]] grows or shrinks.<ref name="Lagassé2000">{{cite book |author=Lagassé, Paul |title=The Columbia Encyclopedia |publisher=Columbia University Press |location=New York |year=2000 |chapter=Monetarism |isbn=0-7876-5015-3 |edition=6th |url-access=registration |url=https://archive.org/details/columbiaencyclop00laga }}</ref>


Monetarists assert that the empirical study of monetary history shows that inflation has always been a monetary phenomenon. The quantity theory of money, simply stated, says that any change in the amount of money in a system will change the price level. This theory begins with the [[equation of exchange]]:
The quantity theory of money, simply stated, says that any change in the amount of money in a system will change the price level. This theory begins with the [[equation of exchange]]:


:<math>MV = PQ</math>
:<math>MV = PQ,</math>
where
where
:<math>M</math> is the nominal quantity of money;
:<math>M</math> is the nominal quantity of money;
:<math>V</math> is the [[velocity of money]] in final expenditures;
:<math>V</math> is the [[velocity of money]] in final expenditures;
:<math>P</math> is the general price level;
:<math>P</math> is the general price level;
:<math>Q</math> is an index of the [[real versus nominal value (economics)|real value]] of final expenditures;
:<math>Q</math> is an index of the [[real versus nominal value (economics)|real value]] of final expenditures.


In this formula, the general price level is related to the level of real economic activity (''Q''), the quantity of money (''M'') and the velocity of money (''V''). The formula is an identity because the velocity of money (''V'') is defined to be the ratio of final nominal expenditure (<math> PQ </math>) to the quantity of money (''M'').
In this formula, the general price level is related to the level of real economic activity (''Q''), the quantity of money (''M'') and the velocity of money (''V''). The formula itself is simply an uncontroversial [[accounting identity]] because the velocity of money (''V'') is defined residually from the equation to be the ratio of final nominal expenditure (<math> PQ </math>) to the quantity of money (''M'').<ref name=Mankiw2002/>{{rp|81–107}}


Monetarists assume that the velocity of money is unaffected by monetary policy (at least in the long run), and the real value of output is determined in the long run by the productive capacity of the economy. Under these assumptions, the primary driver of the change in the general price level is changes in the quantity of money. With exogenous velocity (that is, velocity being determined externally and not being influenced by monetary policy), the money supply determines the value of nominal output (which equals final expenditure) in the short run.
Monetarists assumed additionally that the velocity of money is unaffected by monetary policy (at least in the long run), that the real value of output is also [[exogenous]] in the long run, its long-run value being determined independently by the productive capacity of the economy, and that money supply is exogenous and can be controlled by the monetary authorities. Under these assumptions, the primary driver of the change in the general price level is changes in the quantity of money.<ref name=Mankiw2002/>{{rp|81–107}} Consequently, monetarists contended that monetary policy, not fiscal policy, was the most potent instrument to influence aggregate demand, real output and eventually inflation. This was contrary to Keynesian thinking which in principle recognized a role for monetary policy, but in practice believed that the effect from interest rate changes to the real economy was slight, making monetary policy an ineffective instrument, preferring fiscal policy.<ref name=Blanchard/>{{rp|528}} Conversely, monetarists considered fiscal policy, or government spending and taxation, as ineffective in controlling inflation.<ref name="Lagassé2000"/>


In practice, velocity is not exogenous in the short run, and so the formula does not necessarily imply a stable short-run relationship between the money supply and nominal output. However, in the long run, changes in velocity are assumed to be determined by the evolution of the payments mechanism. If velocity is relatively unaffected by monetary policy, the long-run rate of increase in prices (the inflation rate) is equal to the long-run growth rate of the money supply plus the exogenous long-run rate of velocity growth minus the long run growth rate of real output.<ref name="Mankiw 2002 pp=81–107">{{Harvnb|Mankiw|2002|pp=81–107}}</ref>
Friedman also took issue with the traditional Keynesian view concerning the Phillips curve. He, together with [[Edmund Phelps]], contended that the trade-off between inflation and unemployment implied by the Phillips curve was only temporary, but not permanent. If politicians tried to exploit it, it would eventually disappear because higher inflation would over time be built into the economic expectations of households and firms.<ref name=Blanchard/>{{rp|528–529}} This line of thinking led to the concept of [[potential output]] (sometimes called the "natural gross domestic product"), a level of GDP where the economy is stable in the sense that inflation will neither decrease nor increase. This level may itself change over time when institutional or natural constraints change. It corresponds to the Non-Accelerating Inflation Rate of Unemployment, [[NAIRU]], or the "natural" rate of unemployment (sometimes called the "structural" level of unemployment).<ref name=Blanchard/> If GDP exceeds its potential (and unemployment consequently is below the NAIRU), the theory says that inflation will ''accelerate'' as suppliers increase their prices. If GDP falls below its potential level (and unemployment is above the NAIRU), inflation will ''decelerate'' as suppliers attempt to fill excess capacity, cutting prices and undermining inflation.<ref>{{cite journal | last = Coe | first = David T. | title = Nominal Wages. The NAIRU and Wage Flexibility | publisher=Organisation for Economic Co-operation and Development (OECD) | url = http://www.oecd.org/dataoecd/59/19/33917832.pdf | year=1985 | id = MPRA Paper 114295 | journal = OECD Economic Studies | issue = 5 | pages=87–126 | s2cid=18879396 | access-date=February 24, 2010 | archive-date = February 26, 2018 | archive-url = https://web.archive.org/web/20180226211933/http://www.oecd.org/dataoecd/59/19/33917832.pdf | url-status = live }}</ref>


=== Rational expectations theory ===
====Rational expectations theory====
{{Further|Rational expectations}}


{{Further|Rational expectations theory}}
In the early 1970s, [[rational expectations theory]] led by economists like [[Robert Lucas Jr.|Robert Lucas]], [[Thomas J. Sargent|Thomas Sargent]] and [[Robert Barro]] transformed macroeconomic thinking radically. They held that economic actors look rationally into the future when trying to maximize their well-being, and do not respond solely to immediate [[opportunity cost]]s and pressures.<ref name=Blanchard/>{{rp|529–530}} In this view, future expectations and strategies are important for inflation as well. One implication was that agents would anticipate the likely behaviour of central banks and base their own actions on these expectations. A central bank having a reputation of being "soft" on inflation will generate high inflation expectations, which again will be self-fulfilling when all agents build expectations of future high inflation into their nominal contracts like wage agreements. On the other hand, if the central bank has a reputation of being "tough" on inflation, then such a policy announcement will be believed and inflationary expectations will come down rapidly, thus allowing inflation itself to come down rapidly with minimal economic disruption. The implication is that [[credibility]] becomes very important for central banks in fighting inflation.<ref name=Blanchard/>{{rp|467–469}}


Rational expectations theory holds that economic actors look rationally into the future when trying to maximize their well-being, and do not respond solely to immediate opportunity costs and pressures. In this view, while generally grounded in monetarism, future expectations and strategies are important for inflation as well.
==== New Keynesians ====
Events during the 1970s proved Milton Friedman and other critics of the traditional Phillips curve right: The relation between the inflation rate and the unemployment rate broke down. Eventually, a consensus was established that the break-down was due to agents changing their inflation expectations, confirming Friedman's theory. As a consequence, the notion of a [[natural rate of unemployment]] (alternatively called the structural rate of unemployment) was accepted by most economists, meaning that there is a specific level of unemployment that is compatible with stable inflation. [[Stabilization policy]] must therefore try to steer economic activity so that the actual unemployment rate converges towards that level.<ref name=Blanchard/>{{rp|176–189}} The trade-off between the [[unemployment rate]] and inflation implied by Phillips thus holds in the short term, but not in the long term.<ref>Chang, R. (1997) [https://www.frbatlanta.org/filelegacydocs/ACFC7.pdf "Is Low Unemployment Inflationary?"] {{webarchive|url=https://web.archive.org/web/20131113212953/https://www.frbatlanta.org/filelegacydocs/ACFC7.pdf|date=November 13, 2013}} ''Federal Reserve Bank of Atlanta Economic Review'' 1Q97: 4–13.</ref> Also the [[1970s energy crisis|oil crises of the 1970s]] causing at the same time rising unemployment and rising inflation (i.e. [[stagflation]]) led to a broad recognition by economists that [[supply shock]]s could independently affect inflation.<ref name=parkin/><ref name=Blanchard/>{{rp|529}}


A core assertion of rational expectations theory is that actors will seek to "head off" central-bank decisions by acting in ways that fulfill predictions of higher inflation. This means that central banks must establish their credibility in fighting inflation, or economic actors will make bets that the central bank will expand the money supply rapidly enough to prevent recession, even at the expense of exacerbating inflation.  Thus, if a central bank has a reputation as being "soft" on inflation, when it announces a new policy of fighting inflation with restrictive monetary growth economic agents will not believe that the policy will persist; their inflationary expectations will remain high, and so will inflation. On the other hand, if the central bank has a reputation of being "tough" on inflation, then such a policy announcement will be believed and inflationary expectations will come down rapidly, thus allowing inflation itself to come down rapidly with minimal economic disruption.
During the 1980s a group of researchers named [[New Keynesian economics|new Keynesians]] emerged who accepted many originally non-Keynesian concepts like the importance of monetary policy, the existence of a natural level of unemployment and the incorporation of rational expectations formation as a reasonable benchmark. At the same time they believed, like Keynes did, that various [[market imperfection]]s in different markets like labour markets and financial markets were also important to study to understand both inflation generation and [[business cycle]]s.<ref name=Blanchard/>{{rp|533–534}} During the 1980s and 1990s, there were often heated intellectual debates between new Keynesians and new classicals, but by the 2000s, a synthesis gradually emerged. The result has been called the ''new Keynesian model'',<ref name=Blanchard/>{{rp|535}} the "[[new neoclassical synthesis]]"<ref name=Goodfriend>{{cite journal |last1=Goodfriend |first1=Marvin |title=How the World Achieved Consensus on Monetary Policy |journal=Journal of Economic Perspectives |date=1 November 2007 |volume=21 |issue=4 |pages=47–68 |doi=10.1257/jep.21.4.47|s2cid=56338417 |doi-access=free }}</ref><ref>{{cite journal |last1=Woodford |first1=Michael |title=Convergence in Macroeconomics: Elements of the New Synthesis |journal=American Economic Journal: Macroeconomics |date=1 January 2009 |volume=1 |issue=1 |pages=267–279 |doi=10.1257/mac.1.1.267}}</ref> or simply the "new consensus" model.<ref name=Goodfriend/>


===Heterodox views===
=== View post-2000 to present ===
A common view beginning around the year 2000 and holding through to the present time on inflation and its causes can be illustrated by a modern Phillips curve including a role for supply shocks and inflation expectations beside the original role of aggregate demand (determining employment and unemployment fluctuations) in influencing the inflation rate.<ref name=Blanchard/> Consequently, demand shocks, supply shocks and inflation expectations are all potentially important determinants of inflation,<ref name=congress/> confirming the basis of the older [[triangle model]] by [[Robert J. Gordon]]:<ref>Robert J. Gordon (1988), ''Macroeconomics: Theory and Policy'', 2nd ed., Chap. 22.4, 'Modern theories of inflation'. McGraw-Hill.</ref>


Additionally, there are theories about inflation accepted by economists outside of the [[mainstream economics|mainstream]].
* ''Demand shocks'' may both decrease and increase inflation. So-called [[demand-pull inflation]] may be caused by increases in aggregate demand due to increased private and government spending,<ref>{{cite web |last1=Gillespie |first1=Nick |last2=Taylor |first2=Regan |title=Biden Is Clueless About Inflation |url=https://reason.com/video/2022/04/01/biden-is-clueless-about-inflation/ |website=reason.com |date=April 2022 |publisher=Reason |access-date=4 April 2022 |archive-date=April 27, 2022 |archive-url=https://web.archive.org/web/20220427225435/https://reason.com/video/2022/04/01/biden-is-clueless-about-inflation/ |url-status=live }}</ref><ref>{{cite web |last1=De Rugy |first1=Veronique |title=Blame Insane Government Spending for Inflation |url=https://reason.com/2022/03/31/blame-insane-government-spending-for-inflation/ |website=reason.com |date=March 31, 2022 |publisher=Reason |access-date=4 April 2022 |archive-date=May 11, 2022 |archive-url=https://web.archive.org/web/20220511170305/https://reason.com/2022/03/31/blame-insane-government-spending-for-inflation/ |url-status=live }}</ref> etc. Conversely, negative demand shocks may be caused by [[contractionary]] economic policy.
* ''Supply shocks'' may also lead to both higher or lower inflation, depending on the character of the shock. [[Cost-push inflation]] is caused by a drop in aggregate supply (potential output). This may be due to natural disasters, war or increased prices of inputs. For example, a sudden decrease in the supply of oil, leading to increased oil prices, can cause cost-push inflation. Producers for whom oil is a part of their costs could then pass this on to consumers in the form of increased prices.<ref name=Britannica>{{cite web|url=https://www.britannica.com/EBchecked/topic/287700/inflation/3512/The-cost-push-theory|title=Encyclopædia Britannica|access-date=September 13, 2014|archive-date=September 7, 2014|archive-url=https://web.archive.org/web/20140907030214/http://www.britannica.com/EBchecked/topic/287700/inflation/3512/The-cost-push-theory/|url-status=live}}</ref>
* ''Inflation expectations'' play a major role in forming actual inflation. High inflation can prompt employees to demand rapid wage increases to keep up with consumer prices. In this way, rising wages in turn can help fuel inflation as firms pass these higher labor costs on to their customers as higher prices, leading to a feedback loop. In the case of collective bargaining, wage growth may be set as a function of inflationary expectations, which will be higher when inflation is high. This can cause a [[wage-price spiral]]. In a sense, inflation begets further inflationary expectations, which beget further [[built-in inflation|(built-in) inflation]].<ref name=Britannica/>


==== Austrian view ====
The important role of [[rational expectations]] is recognized by the emphasis on credibility on the part of central banks and other [[policy-makers]].<ref name=Goodfriend/> The monetarist assertion that monetary policy alone could successfully control inflation formed part of the new consensus which recognized that both monetary and fiscal policy are important tools for influencing aggregate demand.<ref name=Goodfriend/><ref name=Blanchard/>{{rp|528}} Indeed, monetary policy is under normal circumstances considered to be the preferable instrument to contain inflation.<ref name=congress>{{cite web |title=Inflation in the U.S. Economy: Causes and Policy Options |url=https://crsreports.congress.gov/product/pdf/R/R47273/2 |website=crsreports.congress.gov |publisher=Congressional Research Service |access-date=15 October 2023 |date=October 6, 2022}}</ref><ref name=Blanchard/> At the same time, most central banks have abandoned trying to target money growth as originally advocated by the monetarists. Instead, most central banks in developed countries focus on adjusting interest rates to achieve an explicit inflation target.<ref name=Romer/><ref name=Blanchard/>{{rp|505–509}} The reason for central bank reluctance in following money growth targets is that the money stock measures that central banks can control tightly, e.g. the [[monetary base]], are not very closely linked to aggregate demand, whereas conversely money supply measures like [[M2 (economics)|M2]], which are in some cases more closely correlated with aggregate demand, are difficult to control for the central bank. Also, in many countries the relationship between aggregate demand and all money stock measures have broken down in recent decades, weakening further the case for monetary policy rules focusing on the money supply.<ref name=Romer/>{{rp|608}}


{{See also|Austrian School|Monetary inflation}}
However, while more disputed in the 1970s, surveys of members of the [[American Economic Association]] (AEA) since the 1990s have shown that most professional American economists generally agree with the statement "Inflation is caused primarily by too much growth in the money supply", while the same surveys have shown a lack of consensus by AEA members since the 1990s that "In the short run, a reduction in unemployment causes the rate of inflation to increase" has developed despite more agreement with the statement in the 1970s.{{refn|name=EconomistsConsensus|<ref>{{cite journal|last1=Kearl|first1=J. R.|last2=Pope|first2=Clayne L.|last3=Whiting|first3=Gordon C.|last4=Wimmer|first4=Larry T.|year=1979|title=A Confusion of Economists?|journal=American Economic Review|publisher=American Economic Association|volume=69|issue=2|pages=28–37|jstor=1801612}}</ref><ref>{{Cite journal |last1=Alston |first1=Richard M. |last2=Kearl |first2=J.R. |author-link2=James R. Kearl |last3=Vaughan |first3=Michael B. |title=Is There a Consensus Among Economists in the 1990's? |date=May 1992 |journal=[[The American Economic Review]] |volume=82 |issue=2 |pages=203–209 |jstor=2117401 |url=http://www.weber.edu/wsuimages/AcademicAffairs/ProvostItems/global.pdf |archive-date=April 8, 2017 |access-date=October 16, 2023 |archive-url=https://web.archive.org/web/20170408191354/http://www.weber.edu/wsuimages/AcademicAffairs/ProvostItems/global.pdf }}</ref><ref>{{Cite journal |last1=Fuller |first1=Dan |last2=Geide-Stevenson |first2=Doris |title=Consensus Among Economists: Revisited |date=Fall 2003 |journal=[[Journal of Economic Education|The Journal of Economic Education]] |volume=34 |issue=4 |pages=369–387 |jstor=30042564 |doi=10.1080/00220480309595230|s2cid=143617926 }}</ref><ref>{{cite journal|last1=Fuller|first1=Dan|last2=Geide-Stevenson|first2=Doris|title=Consensus Among Economists – An Update|year=2014|journal=[[Journal of Economic Education|The Journal of Economic Education]]|publisher=[[Taylor & Francis]]|volume=45|issue=2|page=138|doi=10.1080/00220485.2014.889963|s2cid=143794347|url=https://www.researchgate.net/publication/261884738}}</ref><ref>{{cite journal|last1=Geide-Stevenson|first1=Doris|last2=La Parra-Perez|first2=Alvaro|year=2024|title=Consensus among economists 2020—A sharpening of the picture|journal=[[Journal of Economic Education]]|publisher=[[Taylor & Francis]]|volume=55|issue=4|pages=461–478|doi=10.1080/00220485.2024.2386328}}</ref>}}


The [[Austrian School]] stresses that inflation is not uniform over all assets, goods, and services. Inflation depends on differences in markets and on where newly created money and credit enter the economy. [[Ludwig von Mises]] said that inflation should refer to an increase in the quantity of money, that is not offset by a corresponding increase in the need for money, and that price inflation will necessarily follow, always leaving a poorer<ref>{{cite web |last1=Mises |first1=Ludwig von |title=Human Action |url=https://oll.libertyfund.org/quote/ludwig-von-mises-lays-out-five-fundamental-truths-of-monetary-expansion-1949 |website=OLL |access-date=July 17, 2021 |archive-date=September 25, 2021 |archive-url=https://web.archive.org/web/20210925084337/https://oll.libertyfund.org/quote/ludwig-von-mises-lays-out-five-fundamental-truths-of-monetary-expansion-1949 |url-status=live }}</ref> nation.<ref>{{cite book|last=Von Mises|first=Ludwig|title=The Theory of Money and Credit|year=1912|publisher=Yale University Press|page=240|url=https://mises.org/books/tmc.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://mises.org/books/tmc.pdf |archive-date=2022-10-09 |url-status=live|edition=1953|access-date=January 23, 2014|quote=In theoretical investigation there is only one meaning that can rationally be attached to the expression Inflation: an increase in the quantity of money (in the broader sense of the term, so as to include fiduciary media as well), that is not offset by a corresponding increase in the demand for money (again in the broader sense of the term), so that a fall in the objective exchange-value of money must occur.}}</ref><ref name="TheTheory">The Theory of Money and Credit, Mises (1912, [1981], p. 272)</ref>
[[2021–2023 inflation surge#Housing shortage|Housing shortages]],<ref>{{Cite news |last=Derby |first=Michael S. |date=September 27, 2022 |title=Fed's Harker says housing shortage a key inflation driver |url=https://www.reuters.com/markets/us/feds-harker-says-housing-shortage-key-inflation-driver-2022-09-27/ |work=Reuters}}</ref><ref>{{Cite news |last1=O'Donnell |first1=Katy |last2=Guida |first2=Victoria |date=November 10, 2021 |title=Biden's next inflation threat: The rent is too damn high |url=https://www.politico.com/news/2021/11/10/rent-inflation-biden-520642 |work=Politico |quote=Housing costs just posted one of their largest monthly gains in decades, and many economists expect them to loom large in inflation figures over the next year heading into the 2022 midterm elections. It's not just economists — the Federal Reserve Bank of New York said in research released Monday that Americans on average expect rents to rise 10.1 percent over the next year, the highest reading in the survey's history.}}</ref><ref>{{Cite web |last=Boak |first=Josh |date=2024-03-15 |title=Why are so many voters frustrated by the US economy? It's home prices |url=https://apnews.com/article/biden-inflation-housing-trump-home-price-rent-248ef02e197c3a7ffb801e370c529d33 |access-date=2024-07-24 |website=AP News |language=en |quote=}}</ref><ref>{{Cite news |last=O'Donnell |first=Katy |date=March 18, 2022 |title=The main driver of inflation isn't what you think it is |url=https://www.politico.com/news/2022/03/18/housing-costs-inflation-00015808 |work=Politico |quote=But when it comes to the single biggest driver of runaway prices, Washington's hands are mostly tied. Skyrocketing housing costs may create even bigger problems for the administration going forward than oil and food price spikes, which are the result of sudden and unforeseen — but probably temporary — events. That's because there's no clear end in sight for shelter inflation.}}</ref> [[immigration]]<ref>{{Cite web |last=Condie |first=Stuart |date=2023-07-15 |title=Global Migration Boom Keeps Housing Costs High |url=https://www.wsj.com/economy/global-migration-boom-keeps-housing-costs-high-5fc84b7f |access-date=2025-09-16 |website=The Wall Street Journal |language=en-US}}</ref> and [[2021–2023 inflation surge#Climate change|climate change]]<ref>{{Cite web |last=Borenstein |first=Seth |date=2024-03-21 |title=Higher temperatures mean higher food and other prices. A new study links climate shocks to inflation |url=https://apnews.com/article/inflation-climate-change-food-prices-heat-6e5297e12868aaf797529bb755268818 |access-date=2024-07-24 |website=AP News |language=en}}</ref><ref>{{Cite news |date=July 23, 2024 |title=Home insurance rates are rising due to climate change. What could break that cycle? |url=https://www.npr.org/2024/07/18/1198912918/home-insurance-rates-are-rising-due-to-climate-change-what-could-break-that-cycl |work=NPR}}</ref><ref>{{Cite web |last=Becker |first=William S. |date=2024-07-22 |title=Opinion: Climate inflation is eating your paycheck — and it's only going to get worse |url=https://thehill.com/opinion/energy-environment/4782252-climate-inflation-economic-impact/ |access-date=2024-07-24 |website=The Hill |language=en-US}}</ref><ref>{{Cite web |date=July 11, 2024 |title=How is climate change affecting food prices and inflation? |url=https://www.aljazeera.com/program/inside-story/2024/7/11/how-is-climate-change-affecting-food-prices-and-inflation |access-date=2024-07-24 |website=Al Jazeera |language=en}}</ref> have been cited as significant drivers of inflation in the 21st century.


==== Real bills doctrine ====
====2021–2023 inflation surge====
{{main|2021–2023 inflation surge}}


{{main|Real bills doctrine}}
Most countries experienced the [[2021–2023 inflation surge]], peaking in 2022 and declining in 2023. The causes are believed to be a mixture of demand and supply shocks, whereas inflation expectations generally remained anchored.<ref name="Brookings">{{cite web |last1=Bernanke |first1=Ben |last2=Blanchard |first2=Olivier |title=What Caused the U.S. Pandemic-Era Inflation? |url=https://www.brookings.edu/wp-content/uploads/2023/04/Bernanke-Blanchard-conference-draft_5.23.23.pdf |website=www.brookings.edu |publisher=Hutchins Center on Fiscal and Monetary Policy at the Brookings Institution |access-date=15 October 2023 |date=May 23, 2023}}</ref> Possible causes on the [[Demand shock|demand side]] include [[Stimulus (economics)|expansionary fiscal and monetary policy]] after the [[COVID-19 pandemic]], whereas [[supply shock]]s include the [[2021–2023 global supply chain crisis]] caused by the [[COVID-19 lockdowns]]<ref name="Brookings" /> and the [[Global energy crisis (2021–2023)|global energy crisis]] that was exacerbated by the [[2022 Russian invasion of Ukraine]].


The real bills doctrine (RBD) asserts that banks should issue their money in exchange for short-term real bills of adequate value. As long as banks only issue a dollar in exchange for assets worth at least a dollar, the issuing bank's assets will naturally move in step with its issuance of money, and the money will hold its value. Should the bank fail to get or maintain assets of adequate value, then the bank's money will lose value, just as any financial security will lose value if its asset backing diminishes. The real bills doctrine (also known as the backing theory) thus asserts that inflation results when money outruns its issuer's assets. The quantity theory of money, in contrast, claims that inflation results when money outruns the economy's production of goods.
The term [[sellers' inflation]] was coined during this period to describe the effect of corporate profits as a possible cause of inflation: Price inelasticity can contribute to inflation when [[Consolidation (business)|firms consolidate]], tending to support monopoly or [[monopsony]] conditions anywhere along the [[supply chain]] for goods or services. When this occurs, firms can provide greater [[shareholder value]] by taking a larger proportion of [[Profit (accounting)|profits]] than by investing in providing greater volumes of their outputs.<ref>{{cite book |last1=Mankiw |first1=N. Gregory |title=Principles of economics |date=2015 |publisher=[[Cengage Learning]] |isbn=978-1-285-16587-5 |edition=Seventh |location=Stamford, Connecticut |pages=257–367 |language=en-us |chapter=Part V, chapters 13–17}}</ref><ref>{{cite web |last1=Bivins |first1=Josh |title=Corporate profits have contributed disproportionately to inflation. How should policymakers respond? |url=https://www.epi.org/blog/corporate-profits-have-contributed-disproportionately-to-inflation-how-should-policymakers-respond/ |website=Economic Policy Institute |access-date=25 May 2022 |date=21 April 2022 |archive-date=May 25, 2022 |archive-url=https://web.archive.org/web/20220525111507/https://www.epi.org/blog/corporate-profits-have-contributed-disproportionately-to-inflation-how-should-policymakers-respond/ |url-status=live }}</ref> Shortly after initial energy price shocks caused by the Russian invasion of Ukraine had subsided, oil companies found that supply chain constrictions, already exacerbated by the ongoing global pandemic, supported price inelasticity, i.e., they began lowering prices to match the [[price of oil]] when it fell much more slowly than they had increased their prices when costs rose.<ref>{{cite news |last1=Cronin |first1=Brittany |date=7 May 2022 |title=The good times are rolling for Big Oil. 3 things to know about their surging profits |url=https://www.npr.org/2022/05/07/1097177459/big-oil-exxon-earnings-gasoline-prices-crude |url-status=live |archive-url=https://web.archive.org/web/20220521123900/https://www.npr.org/2022/05/07/1097177459/big-oil-exxon-earnings-gasoline-prices-crude |archive-date=May 21, 2022 |access-date=25 May 2022 |work=NPR |language=en}}</ref>


Currency and banking schools of economics argue the RBD, that banks should also be able to issue currency against bills of trading, which is "real bills" that they buy from merchants. This theory was important in the 19th century in debates between "Banking" and "Currency" schools of monetary soundness, and in the formation of the [[Federal Reserve]]. In the wake of the collapse of the international gold standard post 1913, and the move towards deficit financing of government, RBD has remained a minor topic, primarily of interest in limited contexts, such as [[currency board]]s. It is generally held in ill repute today, with [[Frederic Mishkin]], a governor of the [[Federal Reserve]] going so far as to say it had been "completely discredited."
The [[quantity theory of money]] has long been popular with [[libertarian-conservative]] critics of the [[Federal Reserve]]. During the COVID pandemic and its immediate aftermath, the M2 money supply increased at the fastest rate in decades, leading some to link the growth to the 2021-2023 inflation surge. Fed chairman [[Jerome Powell]] said in December 2021 that the once-strong link between the money supply and inflation "ended about 40 years ago," due to financial innovations and deregulation. Previous Fed chairs [[Ben Bernanke]] and [[Alan Greenspan]], had previously concurred with this position. The broadest measure of [[money supply]], M2, increased about 45% from 2010 through 2015, far faster than GDP growth, yet the inflation rate declined during that period — the opposite of what monetarism would have predicted. A lower [[velocity of money]] than was historically the case<ref>{{cite news |title=Velocity of M2 Money Stock |url=https://fred.stlouisfed.org/series/M2V |publisher=[[Federal Reserve Bank of St. Louis]]}}</ref> was also cited for a diminished effect of growth in the money supply on inflation.<ref>{{cite news |last1=Hanke |first1=Steve H. |last2=John Greenwood |title=Inflation Was Always a Monetary Phenomenon, Never Transitory |url=https://www.nationalreview.com/2024/01/inflation-was-always-a-monetary-phenomenon-never-transitory/ |work=[[National Review]] |date=January 15, 2024}}</ref><ref>{{cite news |last1=Lynch |first1=David J. |title=Inflation has Fed critics pointing to spike in money supply |url=https://www.washingtonpost.com/business/2022/02/06/federal-reserve-inflation-money-supply/ |newspaper=[[The Washington Post]] |date=February 6, 2022}}</ref>


The debate between currency, or quantity theory, and the [[British Banking School|banking schools]] during the 19th century prefigures current questions about the credibility of money in the present. In the 19th century, the banking schools had greater influence in policy in the United States and Great Britain, while the [[British Currency School|currency schools]] had more influence "on the continent", that is in non-British countries, particularly in the [[Latin Monetary Union]] and the [[Scandinavian Monetary Union]].
Surveys of economists conducted by the [[University of Chicago Booth School of Business]] in November 2021 and January 2022 showed that more economists agreed than disagreed (with many expressing uncertainty) that while contributing to rising prices in the United States, the global supply chain crisis would not contribute to a higher long-term inflation rate above the Federal Reserve's [[Inflation targeting|inflation target]] and was not the main driver of the inflation surge, but that the combined effect of the stimulative fiscal and monetary policies being implemented in the United States posed a risk of prolonged higher inflation.<ref>{{cite web|title=Inflation|date=November 23, 2021|publisher=University of Chicago Booth School of Business|url=https://kentclarkcenter.org/surveys/inflation/|access-date=February 5, 2026}}</ref><ref>{{cite web|title=Global Supply Chains|date=January 25, 2022|publisher=University of Chicago Booth School of Business|url=https://kentclarkcenter.org/surveys/global-supply-chains/|access-date=February 5, 2026}}</ref>


In 2019, monetary historians [[Thomas M. Humphrey]] and [[Richard H. Timberlake]] published "Gold, the Real Bills Doctrine, and the Fed: Sources of Monetary Disorder 1922–1938".<ref>{{cite book |last1=Humphrey |first1=Thomas M. |last2=Timberlake |first2=Richard H. |title=Gold, the Real Bills Doctrine, and the Fed : sources of monetary disorder 1922–1938 |publisher=Cato Institute |location=Washington, D.C. |isbn=978-1-948647-13-7 |edition=First}}</ref>
===Heterodox views===
 
Additionally, there are theories about inflation accepted by economists outside of the [[mainstream economics|mainstream]]. The [[Austrian School]] stresses that inflation is not uniform over all assets, goods, and services. Inflation depends on differences in markets and on where newly created money and credit enter the economy. [[Ludwig von Mises]] said that inflation should refer to an increase in the quantity of money, that is not offset by a corresponding increase in the need for money, and that price inflation will necessarily follow, always leaving a poorer nation.<ref>{{cite web |last1=Mises |first1=Ludwig von |title=Human Action |url=https://oll.libertyfund.org/quote/ludwig-von-mises-lays-out-five-fundamental-truths-of-monetary-expansion-1949 |website=OLL |access-date=July 17, 2021 |archive-date=September 25, 2021 |archive-url=https://web.archive.org/web/20210925084337/https://oll.libertyfund.org/quote/ludwig-von-mises-lays-out-five-fundamental-truths-of-monetary-expansion-1949 |url-status=live }}</ref><ref>{{cite book|last=Von Mises|first=Ludwig|title=The Theory of Money and Credit|year=1912|publisher=Yale University Press|page=240|url=https://mises.org/books/tmc.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://mises.org/books/tmc.pdf |archive-date=2022-10-09 |url-status=live|edition=1953|access-date=January 23, 2014|quote=In theoretical investigation there is only one meaning that can rationally be attached to the expression Inflation: an increase in the quantity of money (in the broader sense of the term, so as to include fiduciary media as well), that is not offset by a corresponding increase in the demand for money (again in the broader sense of the term), so that a fall in the objective exchange-value of money must occur.}}</ref><ref>The Theory of Money and Credit, Mises (1912, [1981]), p. 272.</ref>
== Effects of inflation ==


=== General effect ===
=== Government debt ===
[[File:Restaurant increasing prices by $1.00 due to inflation.jpg|thumb|Restaurant increasing prices by $1.00 due to inflation]]
[[Government debt]] obligates the government to increase taxes, reduce spending or the government may resort to inflationary finance of the deficit.<ref name=":0">{{Cite journal |last=Aimola |first=Akingbade U. |last2=Odhiambo |first2=Nicholas M. |date=2020-06-01 |title=Public Debt and Inflation: A Review of International Literature |url=https://www.sciendo.com/article/10.2478/foli-2020-0001 |journal=Folia Oeconomica Stetinensia |language=en |volume=20 |issue=1 |pages=9–24 |doi=10.2478/foli-2020-0001 |issn=1898-0198|doi-access=free }}</ref><ref name=":1">{{Cite web |title=The Inflationary Risks of Rising Federal Deficits and Debt {{!}} The Budget Lab at Yale |url=https://budgetlab.yale.edu/research/inflationary-risks-rising-federal-deficits-and-debt |access-date=2026-02-03 |website=budgetlab.yale.edu |language=en}}</ref> Another direction which translates [[government debt]] to inflation is the motivation of governments to erode nominal debts by increasing inflation.<ref name=":0" /><ref name=":1" /> As a result, elevated debt heightens the risk of inflationary pressures in both the short and long run by boosting [[aggregate demand]], shaping inflation expectations, crowding out private investment, and raising concerns about [[fiscal dominance]].<ref name=":1" /> It was found that in the short run, a permanent 1 percent of [[Gross domestic product|GDP]] increase in the primary deficit leads, after five years, to inflationary pressures equivalent to a $300–$1,250 loss in household purchasing power per household (in 2024 dollars).<ref name=":1" />


Inflation is the decrease in the purchasing power of a currency. That is, when the general level of prices rise, each monetary unit can buy fewer goods and services in aggregate. The effect of inflation differs on different sectors of the economy, with some sectors being adversely affected while others benefitting. For example, with inflation, those segments in society which own physical assets, such as property, stock etc., benefit from the price/value of their holdings going up, when those who seek to acquire them will need to pay more for them. Their ability to do so will depend on the degree to which their income is fixed. For example, increases in payments to workers and pensioners often lag behind inflation, and for some people income is fixed. Also, individuals or institutions with cash assets will experience a decline in the purchasing power of the cash. Increases in the price level (inflation) erode the real value of money (the functional currency) and other items with an underlying monetary nature.
==Effects of inflation==
===General effect===
[[File:Restaurant increasing prices by $1.00 due to inflation.jpg|thumb|upright=1.2|Restaurant increasing prices by $1.00 due to inflation]]
Inflation is the decrease in the purchasing power of a currency. That is, when the general level of prices rise, each monetary unit can buy fewer goods and services in aggregate. The effect of inflation differs on different sectors of the economy, with some sectors being adversely affected while others benefitting. For example, with inflation, those segments in society which own physical assets, such as property, stock etc., benefit from the price/value of their holdings going up, when those who seek to acquire them will need to pay more for them. Their ability to do so will depend on the degree to which their income is fixed. For example, increases in payments to workers and pensioners often lag behind inflation, and for some people income is fixed. Also, individuals or institutions with cash assets will experience a decline in the purchasing power of the cash. Increases in the price level (inflation) erode the real value of money (the functional currency) and other items with an underlying monetary nature.


Debtors who have debts with a fixed nominal rate of interest will see a reduction in the "real" interest rate as the inflation rate rises. The real interest on a loan is the nominal rate minus the inflation rate. The formula ''R = N-I'' approximates the correct answer as long as both the nominal interest rate and the inflation rate are small. The correct equation is ''r = n/i'' where ''r'', ''n'' and ''i'' are expressed as [[ratio]]s (e.g. 1.2 for +20%, 0.8 for −20%). As an example, when the inflation rate is 3%, a loan with a nominal interest rate of 5% would have a real interest rate of approximately 2% (in fact, it's 1.94%). Any unexpected increase in the inflation rate would decrease the real interest rate. Banks and other lenders adjust for this inflation risk either by including an inflation risk premium to fixed interest rate loans, or lending at an adjustable rate.
Debtors who have debts with a fixed nominal rate of interest will see a reduction in the "real" interest rate as the inflation rate rises. The real interest on a loan is the nominal rate minus the inflation rate. The formula ''R = N-I'' approximates the correct answer as long as both the nominal interest rate and the inflation rate are small. The correct equation is ''r = n/i'' where ''r'', ''n'' and ''i'' are expressed as [[ratio]]s (e.g. 1.2 for +20%, 0.8 for −20%). As an example, when the inflation rate is 3%, a loan with a nominal interest rate of 5% would have a real interest rate of approximately 2% (in fact, it's 1.94%). Any unexpected increase in the inflation rate would decrease the real interest rate. Banks and other lenders adjust for this inflation risk either by including an inflation risk premium to fixed interest rate loans or lending at an adjustable rate.


=== Negative ===
=== Negative ===
[[File:30.04.2022-Lula com Mulheres pelo Direito à Alimentação (52302798877).jpg|thumb|Inflation is illustrated by the contrast between what [[Brazilian real|R$]]100 could buy in 2010 and in 2022, observed by [[Lula]] during a meeting with women in Brasilândia.]]
High or unpredictable inflation rates are regarded as harmful to an overall economy. They add inefficiencies in the market and make it difficult for companies to budget or plan long-term. Inflation can act as a drag on productivity as companies are forced to shift resources away from products and services to focus on profit and losses from currency inflation.<ref name="Taylor" /> Uncertainty about the future purchasing power of money discourages investment and saving.<ref>{{cite journal | title=Personal Savings and Anticipated Inflation | journal=The Economic Journal | last=Bulkley | first=George | volume=91 | issue=361 |date=March 1981| pages=124–135 | doi=10.2307/2231702 | jstor=2231702}}</ref> Inflation hurts asset prices such as stock performance in the short-run, as it erodes non-energy corporates' profit margins and leads to [[central bank]]s' policy tightening measures.<ref>{{Cite web |title=Stock Returns and Inflation Redux: An Explanation from Monetary Policy in Advanced and Emerging Markets |url=https://www.imf.org/en/Publications/WP/Issues/2021/08/20/Stock-Returns-and-Inflation-Redux-An-Explanation-from-Monetary-Policy-in-Advanced-and-463391 |access-date=2023-01-08 |website=IMF |language=en |archive-date=January 8, 2023 |archive-url=https://web.archive.org/web/20230108213505/https://www.imf.org/en/Publications/WP/Issues/2021/08/20/Stock-Returns-and-Inflation-Redux-An-Explanation-from-Monetary-Policy-in-Advanced-and-463391 |url-status=live }}</ref> Inflation can also impose hidden tax increases. For instance, inflated earnings push taxpayers into higher income tax rates unless the [[Tax bracket|tax brackets]] are indexed to inflation.


High or unpredictable inflation rates are regarded as harmful to an overall economy. They add inefficiencies in the market, and make it difficult for companies to budget or plan long-term. Inflation can act as a drag on productivity as companies are forced to shift resources away from products and services to focus on profit and losses from currency inflation.<ref name=Taylor /> Uncertainty about the future purchasing power of money discourages investment and saving.<ref>{{cite journal | title=Personal Savings and Anticipated Inflation | journal=The Economic Journal | last=Bulkley | first=George | volume=91 | issue=361 | pages=124–135 | doi=10.2307/2231702 | jstor=2231702}}</ref> Inflation hurts asset prices such as stock performance in the short-run, as it erodes non-energy corporates' profit margins and leads to central banks' policy tightening measures.<ref>{{Cite web |title=Stock Returns and Inflation Redux: An Explanation from Monetary Policy in Advanced and Emerging Markets |url=https://www.imf.org/en/Publications/WP/Issues/2021/08/20/Stock-Returns-and-Inflation-Redux-An-Explanation-from-Monetary-Policy-in-Advanced-and-463391 |access-date=2023-01-08 |website=IMF |language=en |archive-date=January 8, 2023 |archive-url=https://web.archive.org/web/20230108213505/https://www.imf.org/en/Publications/WP/Issues/2021/08/20/Stock-Returns-and-Inflation-Redux-An-Explanation-from-Monetary-Policy-in-Advanced-and-463391 |url-status=live }}</ref> Inflation can also impose hidden tax increases. For instance, inflated earnings push taxpayers into higher income tax rates unless the tax brackets are indexed to inflation.
With high inflation, purchasing power is redistributed from those on fixed nominal incomes, such as some pensioners whose pensions are not indexed to the price level, towards those with variable incomes whose earnings may better keep pace with the inflation.<ref name=Taylor/> This redistribution of purchasing power will also occur between international trading partners. Where fixed [[exchange rate]]s are imposed, higher inflation in one economy than another will cause the first economy's exports to become more expensive and affect the [[balance of trade]]. There can also be negative effects to trade from an increased instability in currency exchange prices caused by unpredictable inflation.
 
With high inflation, purchasing power is redistributed from those on fixed nominal incomes, such as some pensioners whose pensions are not indexed to the price level, towards those with variable incomes whose earnings may better keep pace with the inflation.<ref name=Taylor /> This redistribution of purchasing power will also occur between international trading partners. Where fixed [[exchange rate]]s are imposed, higher inflation in one economy than another will cause the first economy's exports to become more expensive and affect the [[balance of trade]]. There can also be negative effects to trade from an increased instability in currency exchange prices caused by unpredictable inflation.


;[[Hoarding]]: People buy durable and/or non-perishable commodities and other goods as stores of wealth, to avoid the losses expected from the declining purchasing power of money, creating shortages of the hoarded goods.
;[[Hoarding]]: People buy durable and/or non-perishable commodities and other goods as stores of wealth, to avoid the losses expected from the declining purchasing power of money, creating shortages of the hoarded goods.


;Social unrest and revolts: Inflation can lead to massive demonstrations and revolutions. For example, inflation and in particular food inflation is considered one of the main reasons that caused the 2010–11 [[Tunisian revolution]]<ref>"Les Egyptiens souffrent aussi de l'accélération de l'inflation", Céline Jeancourt-Galignani{{snd}} La Tribune, February 10, 2011</ref> and the [[2011 Egyptian revolution]],<ref name="tna">{{Cite news|url=http://www.thenewage.co.za/8894-1007-53-Egypt_protests_a_ticking_time_bomb_Analysts|title=Egypt protests a ticking time bomb: Analysts|author=AFP|publisher=The New Age|access-date=January 29, 2011|url-status=dead|archive-url=https://web.archive.org/web/20110209104208/http://www.thenewage.co.za/8894-1007-53-Egypt_protests_a_ticking_time_bomb_Analysts|archive-date=February 9, 2011|df=mdy-all}}</ref> according to many observers including [[Robert Zoellick]],<ref>"Les prix alimentaires proches de "la cote d'alerte"" – Le Figaro, with AFP, February 20, 2011</ref> president of the [[World Bank]]. Tunisian president [[Zine El Abidine Ben Ali]] was ousted, Egyptian President [[Hosni Mubarak]] was also ousted after only 18 days of demonstrations, and protests soon spread in many countries of North Africa and Middle East.
;Social unrest and revolts: Inflation can lead to massive demonstrations and revolutions. [[Thomas J. Sargent|Thomas Sargent]], showed how the huge public debt hoarded by [[Louis XVI]] stimulated the [[French Revolution|French revolution]].<ref>{{Cite journal |last=Sargent |first=Thomas J. |last2=Velde |first2=François R. |date=June 1995 |title=Macroeconomic Features of the French Revolution |url=https://www.journals.uchicago.edu/doi/abs/10.1086/261992 |journal=Journal of Political Economy |volume=103 |issue=3 |pages=474–518 |doi=10.1086/261992 |issn=0022-3808|url-access=subscription }}</ref> After the revolution, inflation replaced debt as a tool for financing the debt.<ref>{{Cite web |title=What the French Revolution Can Teach Us About Inflation |url=https://www.utep.edu/newsfeed/2023/what-the-french-revolution-can-teach-us-about-inflation.html |access-date=2026-02-03 |website=www.utep.edu |language=en-US}}</ref><ref>{{Cite journal |last=Cutsinger |first=Bryan P. |last2=Rouanet |first2=Louis |last3=Ingber |first3=Joshua S. |date=2023-08-01 |title=Assignats or death: The politics and dynamics of hyperinflation in revolutionary France |url=https://www.sciencedirect.com/science/article/pii/S0014292123001393 |journal=European Economic Review |volume=157 |article-number=104510 |doi=10.1016/j.euroecorev.2023.104510 |issn=0014-2921|url-access=subscription }}</ref> The post-revolution hyperinflation is considered as one of the reason for the rise of [[Napoleon]].<ref>{{Cite web |title=Napoleon Rises to Power in France {{!}} History {{!}} Research Starters {{!}} EBSCO Research |url=https://www.ebsco.com/ |access-date=2026-02-03 |website=EBSCO |language=en}}</ref><ref>{{Cite web |last=Linton |first=Marisa |title=How Did Napoleon Bonaparte Come To Power? {{!}} HistoryExtra |url=https://www.historyextra.com/period/georgian/napoleon-gain-power-french-revolution/ |access-date=2026-02-03 |website=www.historyextra.com |language=en}}</ref><ref>{{Cite web |title=Napoleon III confronted with the Economic crisis of 1857-1858 |url=https://www.napoleon.org/en/history-of-the-two-empires/articles/napoleon-iii-confronted-with-the-economic-crisis-of-1857-1858/ |access-date=2026-02-03 |website=napoleon.org |language=en-US}}</ref>  Likewise, the [[Germany|German]] [[Hyperinflation in the Weimar Republic|hyperinflation]] is considered to be one of the reason for the rise of the [[Nazi Party|Nazi party]].<ref>{{Cite journal |last=Ferguson |first=Niall |last2=Granville |first2=Brigitte |date=2000 |title="Weimar on the Volga": Causes and Consequences of Inflation in 1990s Russia Compared with 1920s Germany |url=https://www.jstor.org/stable/2698087 |journal=The Journal of Economic History |volume=60 |issue=4 |pages=1061–1087 |issn=0022-0507}}</ref><ref>{{Cite book |last=Acemoglu |first=Daron |title=Economics: third edition, global edition |last2=Laibson |first2=David I. |last3=List |first3=John A. |date=2022 |publisher=Pearson |isbn=978-1-292-41101-9 |edition=3rd |location=Harlow}}</ref> Inflation and in particular [[food inflation]] is considered one of the main reasons that caused the 2010–2011 [[Tunisian revolution]]<ref>"Les Egyptiens souffrent aussi de l'accélération de l'inflation", Céline Jeancourt-Galignani{{snd}}La Tribune, February 10, 2011.</ref> and the [[2011 Egyptian revolution]],<ref name="tna">{{Cite news|url=http://www.thenewage.co.za/8894-1007-53-Egypt_protests_a_ticking_time_bomb_Analysts|title=Egypt protests a ticking time bomb: Analysts|author=AFP|publisher=The New Age|date=January 27, 2011|access-date=January 29, 2011|archive-url=https://web.archive.org/web/20110209104208/http://www.thenewage.co.za/8894-1007-53-Egypt_protests_a_ticking_time_bomb_Analysts|archive-date=February 9, 2011}}</ref> according to many observers including [[Robert Zoellick]],<ref>"Les prix alimentaires proches de 'la cote d'alerte'" – Le Figaro, with AFP, February 20, 2011.</ref> president of the [[World Bank]]. [[Tunisia|Tunisian]] president [[Zine El Abidine Ben Ali]] was ousted, [[Egypt|Egyptian]] President [[Hosni Mubarak]] was also ousted after only 18 days of demonstrations, and protests soon spread in many countries of North Africa and [[Middle East]]. The high [[inflation in Iran]], especially of [[Food inflation in Iran|food]] is considered as one of the main reasons for the [[2025–2026 Iranian protests|2025-2026 mass protests in Iran]].<ref>{{Cite web |date=2026-01-29 |title=How economic collapse set the stage for Iran's deadly protests |url=https://www.thenewhumanitarian.org/news-feature/2026/01/29/how-economic-collapse-set-stage-iran-deadly-protests |access-date=2026-02-03 |website=www.thenewhumanitarian.org |language=en}}</ref><ref>{{Cite web |title=Iran starts 2026 facing protests, inflation and sanctions |url=https://www.dw.com/en/iran-starts-2026-facing-protests-inflation-and-sanctions/a-75360572 |access-date=2026-02-03 |website=dw.com |language=en}}</ref><ref>{{Cite news |title=2026 Iranian Protests {{!}} Cause, Events, Leaders, 12-Day War, Trump, Islamic Revolution, Reza Pahlavi, Shah, & Israel {{!}} Britannica |url=https://www.britannica.com/event/2026-Iranian-Protests |archive-url=http://web.archive.org/web/20260117172716/https://www.britannica.com/event/2026-Iranian-Protests |archive-date=2026-01-17 |access-date=2026-02-03 |work=Encyclopedia Britannica |language=en}}</ref>


;[[Hyperinflation]]: If inflation becomes too high, it can cause people to severely curtail their use of the currency, leading to an acceleration in the inflation rate. High and accelerating inflation grossly interferes with the normal workings of the economy, hurting its ability to supply goods. Hyperinflation can lead people to abandon the use of the country's currency in favour of external currencies ([[dollarization]]), as has been reported to have occurred in [[North Korea]]).<ref name="cato">{{Cite news|url=http://www.cato.org/publications/commentary/north-korea-hyperinflation-dollarization|title=North Korea: From Hyperinflation to Dollarization?|author=Steve H. Hanke|access-date=August 21, 2014|archive-date=December 26, 2020|archive-url=https://web.archive.org/web/20201226020043/https://www.cato.org/publications/commentary/north-korea-hyperinflation-dollarization|url-status=live}}</ref>
;[[Hyperinflation]]: If inflation becomes too high, it can cause people to severely curtail their use of the currency, leading to an acceleration in the inflation rate. High and accelerating inflation grossly interferes with the normal workings of the economy, hurting its ability to supply goods. Hyperinflation can lead people to abandon the use of the country's currency in favour of external currencies ([[dollarization]]), as has been reported to have occurred in [[North Korea]].<ref>{{Cite news |author=Hanke |first=Steve H. |date=July 2013 |title=North Korea: From Hyperinflation to Dollarization? |url=http://www.cato.org/publications/commentary/north-korea-hyperinflation-dollarization |website=Cato Institute |url-status=live |access-date=August 21, 2014 |archive-url=https://web.archive.org/web/20201226020043/https://www.cato.org/publications/commentary/north-korea-hyperinflation-dollarization |archive-date=December 26, 2020}}</ref>


;[[Allocative efficiency]]: A change in the supply or demand for a good will normally cause its [[relative price]] to change, signaling the buyers and sellers that they should re-allocate resources in response to the new market conditions. But when prices are constantly changing due to inflation, price changes due to genuine relative [[price signal]]s are difficult to distinguish from price changes due to general inflation, so agents are slow to respond to them. The result is a loss of [[economic efficiency|allocative efficiency]].
;[[Allocative efficiency]]: A change in the supply or demand for a good will normally cause its [[relative price]] to change, signaling the buyers and sellers that they should re-allocate resources in response to the new market conditions. But when prices are constantly changing due to inflation, price changes due to genuine relative [[price signal]]s are difficult to distinguish from price changes due to general inflation, so agents are slow to respond to them. The result is a loss of [[economic efficiency|allocative efficiency]].
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;[[Menu cost]]
;[[Menu cost]]
[[File:Subway pizza inflation 2022 jeh.jpg|thumb|Low-cost price adjustment]]
 
: With high inflation, firms must change their prices often to keep up with economy-wide changes. But often changing prices is itself a costly activity whether explicitly, as with the need to print new menus, or implicitly, as with the extra time and effort needed to change prices constantly.
: With high inflation, firms must change their prices often to keep up with economy-wide changes. But often changing prices is itself a costly activity whether explicitly, as with the need to print new menus, or implicitly, as with the extra time and effort needed to change prices constantly.


;[[Inflation tax|Tax]]: Inflation serves as a hidden tax on currency holdings.<ref>{{Cite journal|last1=Cooley|first1=Thomas F.|last2=Hansen|first2=Gary D.|title=The Inflation Tax in a Real Business Cycle Model|url=https://www.jstor.org/stable/1827929|journal=The American Economic Review|volume=79|issue=4|pages=733–748|jstor=1827929|issn=0002-8282|access-date=October 7, 2021|archive-date=October 8, 2021|archive-url=https://web.archive.org/web/20211008164402/https://www.jstor.org/stable/1827929|url-status=live}}</ref><ref>{{Cite web|title=Inflation: A Tax on Money Holdings|url=https://www.economics.utoronto.ca/jfloyd/modules/inft.html|access-date=2021-10-07|website=www.economics.utoronto.ca|archive-date=November 11, 2020|archive-url=https://web.archive.org/web/20201111215101/https://www.economics.utoronto.ca/jfloyd/modules/inft.html|url-status=live}}</ref>
;[[Inflation tax|Tax]]: Inflation serves as a hidden tax on currency holdings.<ref>{{Cite journal|last1=Cooley|first1=Thomas F.|last2=Hansen|first2=Gary D.|date=1989|title=The Inflation Tax in a Real Business Cycle Model|journal=The American Economic Review|volume=79|issue=4|pages=733–748|jstor=1827929|issn=0002-8282}}</ref><ref>{{Cite web|title=Inflation: A Tax on Money Holdings|url=https://www.economics.utoronto.ca/jfloyd/modules/inft.html|access-date=2021-10-07|website=www.economics.utoronto.ca|archive-date=November 11, 2020|archive-url=https://web.archive.org/web/20201111215101/https://www.economics.utoronto.ca/jfloyd/modules/inft.html|url-status=live}}</ref>


=== Positive ===
=== Positive ===
;Labour-market adjustments: Nominal wages are [[Sticky (economics)|slow to adjust downward]]. This can lead to prolonged disequilibrium and high unemployment in the labor market. Since inflation allows real wages to fall even if nominal wages are kept constant, moderate inflation enables labor markets to reach equilibrium faster.<ref>{{cite journal |last1=Tobin |first1=James |date=1972 |title=Inflation and Unemployment |journal=American Economic Review |volume=62 |issue=1 |pages=1–18 |jstor=1821468 }}</ref>


;Labour-market adjustments: Nominal wages are [[Sticky (economics)|slow to adjust downwards]]. This can lead to prolonged disequilibrium and high unemployment in the labor market. Since inflation allows real wages to fall even if nominal wages are kept constant, moderate inflation enables labor markets to reach equilibrium faster.<ref>{{cite journal |last1=Tobin |first1=James |title=Inflation and Unemployment |url=https://www.jstor.org/stable/1821468 |journal=American Economic Review |volume=62 |issue=1 |pages=1–18 |jstor=1821468 |access-date=2023-03-22}}</ref>
;Room to maneuver: The primary tools for controlling the money supply are the ability to set the [[discount window|discount rate]], the rate at which banks can borrow from the central bank, and [[open market operations]], which are the central bank's interventions into the bonds market with the aim of affecting the nominal interest rate. If an economy finds itself in a recession with already low, or even zero, nominal interest rates, then the bank cannot cut these rates further (since negative nominal interest rates are impossible) to stimulate the economy{{snd}}this situation is known as a [[liquidity trap]].


;Room to maneuver: The primary tools for controlling the money supply are the ability to set the [[discount window|discount rate]], the rate at which banks can borrow from the central bank, and [[open market operations]], which are the central bank's interventions into the bonds market with the aim of affecting the nominal interest rate. If an economy finds itself in a recession with already low, or even zero, nominal interest rates, then the bank cannot cut these rates further (since negative nominal interest rates are impossible) to stimulate the economy{{snd}} this situation is known as a [[liquidity trap]].
;Mundell–Tobin effect: According to the Mundell–Tobin effect, an increase in inflation leads to an increase in capital investment, which leads to an increase in growth.<ref>{{Cite web |last=Edwards |first=Jeffrey A. |date=2006 |title=Politics, Inflation, and the Mundell–Tobin Effect |url=https://mpra.ub.uni-muenchen.de/36443/ |access-date=2022-06-09 |website=mpra.ub.uni-muenchen.de |language=en |archive-date=November 1, 2018 |archive-url=https://web.archive.org/web/20181101141711/https://mpra.ub.uni-muenchen.de/36443/ |url-status=live }}</ref> The [[Nobel Memorial Prize in Economic Sciences|Nobel]] laureate [[Robert Mundell]] noted that moderate inflation would induce savers to substitute lending for some money holding as a means to finance future spending. That substitution would cause market clearing real interest rates to fall.<ref>{{cite journal|last=Mundell|first=James|journal=Journal of Political Economy|volume=LXXI|year=1963|pages=280–283 |title=Inflation and Real Interest|issue=3|doi=10.1086/258771|s2cid=153733633}}</ref> The lower real rate of interest would induce more borrowing to finance investment. In a similar vein, Nobel laureate [[James Tobin]] noted that such inflation would cause businesses to substitute investment in [[physical capital]] (plant, equipment, and inventories) for money balances in their asset portfolios. That substitution would mean choosing the making of investments with lower rates of real return. (The rates of return are lower because the investments with higher rates of return were already being made before.)<ref>Tobin, J. ''Econometrica'', Vol. 33, (1965), pp. 671–684 "Money and Economic Growth"</ref> The two related effects are known as the [[Mundell–Tobin effect]]. Unless the economy is already overinvesting according to models of [[Economic growth|economic growth theory]], that extra investment resulting from the effect would be seen as positive.


;Mundell–Tobin effect: According to the Mundell-Tobin effect, an increase in inflation leads to an increase in capital investment, which leads to an increase in growth.<ref>{{Cite web |last=Edwards |first=Jeffrey A. |title=Politics, Inflation, and the Mundell-Tobin Effect |url=https://mpra.ub.uni-muenchen.de/36443/ |access-date=2022-06-09 |website=mpra.ub.uni-muenchen.de |language=en |archive-date=November 1, 2018 |archive-url=https://web.archive.org/web/20181101141711/https://mpra.ub.uni-muenchen.de/36443/ |url-status=live }}</ref> The [[Nobel Memorial Prize in Economic Sciences|Nobel]] laureate [[Robert Mundell]] noted that moderate inflation would induce savers to substitute lending for some money holding as a means to finance future spending. That substitution would cause market clearing real interest rates to fall.<ref>{{cite journal|last=Mundell|first=James|journal=Journal of Political Economy|volume=LXXI|year=1963|pages=280–283 |title=Inflation and Real Interest|issue=3|doi=10.1086/258771|s2cid=153733633}}</ref> The lower real rate of interest would induce more borrowing to finance investment. In a similar vein, Nobel laureate [[James Tobin]] noted that such inflation would cause businesses to substitute investment in [[physical capital]] (plant, equipment, and inventories) for money balances in their asset portfolios. That substitution would mean choosing the making of investments with lower rates of real return. (The rates of return are lower because the investments with higher rates of return were already being made before.)<ref>Tobin, J. Econometrica, Vol. 33, (1965), pp. 671–684 "Money and Economic Growth"</ref> The two related effects are known as the [[Mundell–Tobin effect]]. Unless the economy is already overinvesting according to models of [[Economic growth|economic growth theory]], that extra investment resulting from the effect would be seen as positive.
;Instability with deflation:  Economist [[Sho-Chieh Tsiang|S.C. Tsiang]] noted that once substantial deflation is expected, two important effects will appear; both a result of money holding substituting for lending as a vehicle for saving.<ref>{{cite journal |last1=Tsiang |first1=S. C. |title=A Critical Note on the Optimum Supply of Money |journal=Journal of Money, Credit and Banking |date=1969 |volume=1 |issue=2 |pages=266–280 |doi=10.2307/1991274 |jstor=1991274 |url=https://ideas.repec.org/a/mcb/jmoncb/v1y1969i2p266-80.html |language=en |access-date=October 20, 2020 |archive-date=April 25, 2021 |archive-url=https://web.archive.org/web/20210425223335/https://ideas.repec.org/a/mcb/jmoncb/v1y1969i2p266-80.html |url-status=live |url-access=subscription }}</ref> The first was that continually falling prices and the resulting incentive to hoard money will cause instability resulting from the likely increasing fear, while money hoards grow in value, that the value of those hoards are at risk, as people realize that a movement to trade those money hoards for real goods and assets will quickly drive those prices up. Any movement to spend those hoards "once started would become a tremendous avalanche, which could rampage for a long time before it would spend itself."<ref>Tsiang, 1969 (p. 272).</ref> Thus, a regime of long-term deflation is likely to be interrupted by periodic spikes of rapid inflation and consequent real economic disruptions. The second effect noted by Tsiang is that when savers have substituted money holding for lending on financial markets, the role of those markets in channeling savings into investment is undermined. With nominal interest rates driven to zero, or near zero, from the competition with a high return money asset, there would be no price mechanism in whatever is left of those markets. With financial markets effectively euthanized, the remaining goods and physical asset prices would move in perverse directions. For example, an increased desire to save could not push interest rates further down (and thereby stimulate investment) but would instead cause additional money hoarding, driving consumer prices further down and making investment in consumer goods production thereby less attractive. Moderate inflation, once its expectation is incorporated into nominal interest rates, would give those interest rates room to go both up and down in response to shifting investment opportunities, or savers' preferences, and thus allow financial markets to function in a more normal fashion.
 
;Instability with deflation:  Economist [[Sho-Chieh Tsiang|S.C. Tsiang]] noted that once substantial deflation is expected, two important effects will appear; both a result of money holding substituting for lending as a vehicle for saving.<ref>{{cite journal |last1=Tsiang |first1=S. C. |title=A Critical Note on the Optimum Supply of Money |journal=Journal of Money, Credit and Banking |volume=1 |issue=2 |pages=266–280 |doi=10.2307/1991274 |jstor=1991274 |url=https://ideas.repec.org/a/mcb/jmoncb/v1y1969i2p266-80.html |language=en |access-date=October 20, 2020 |archive-date=April 25, 2021 |archive-url=https://web.archive.org/web/20210425223335/https://ideas.repec.org/a/mcb/jmoncb/v1y1969i2p266-80.html |url-status=live }}</ref> The first was that continually falling prices and the resulting incentive to hoard money will cause instability resulting from the likely increasing fear, while money hoards grow in value, that the value of those hoards are at risk, as people realize that a movement to trade those money hoards for real goods and assets will quickly drive those prices up. Any movement to spend those hoards "once started would become a tremendous avalanche, which could rampage for a long time before it would spend itself."<ref>Tsiang, 1969 (p. 272)</ref> Thus, a regime of long-term deflation is likely to be interrupted by periodic spikes of rapid inflation and consequent real economic disruptions. The second effect noted by Tsiang is that when savers have substituted money holding for lending on financial markets, the role of those markets in channeling savings into investment is undermined. With nominal interest rates driven to zero, or near zero, from the competition with a high return money asset, there would be no price mechanism in whatever is left of those markets. With financial markets effectively euthanized, the remaining goods and physical asset prices would move in perverse directions. For example, an increased desire to save could not push interest rates further down (and thereby stimulate investment) but would instead cause additional money hoarding, driving consumer prices further down and making investment in consumer goods production thereby less attractive. Moderate inflation, once its expectation is incorporated into nominal interest rates, would give those interest rates room to go both up and down in response to shifting investment opportunities, or savers' preferences, and thus allow financial markets to function in a more normal fashion.
 
=== Cost-of-living allowance ===


===Cost-of-living allowance===
{{See also|Cost of living}}
{{See also|Cost of living}}


The real purchasing power of fixed payments is eroded by inflation unless they are inflation-adjusted to keep their real values constant. In many countries, employment contracts, pension benefits, and government entitlements (such as [[social security]]) are tied to a cost-of-living index, typically to the [[consumer price index]].<ref name="cola wars">{{cite web |url=http://www.govexec.com/dailyfed/0906/090806rp.htm |title=COLA Wars |work=Government Executive |publisher=[[National Journal Group]] |access-date=September 23, 2008 |last=Flanagan |first=Tammy |archive-url=https://web.archive.org/web/20081005120234/http://www.govexec.com/dailyfed/0906/090806rp.htm |archive-date=October 5, 2008 |url-status=dead }}</ref> A ''cost-of-living adjustment'' (COLA) adjusts salaries based on changes in a cost-of-living index.<ref>{{Cite web|url=https://www.ssa.gov/oact/cola/colasummary.html|title=Cost-Of-Living Adjustment (COLA)|last=SueKunkel|website=www.ssa.gov|language=en|access-date=2018-05-15|archive-date=November 27, 2021|archive-url=https://web.archive.org/web/20211127155725/https://www.ssa.gov/OACT/COLA/colasummary.html|url-status=live}}</ref> It does not control inflation, but rather seeks to mitigate the consequences of inflation for those on fixed incomes. Salaries are typically adjusted annually in low inflation economies. During hyperinflation they are adjusted more often.<ref name="cola wars" /> They may also be tied to a cost-of-living index that varies by geographic location if the employee moves.
The real purchasing power of fixed payments is eroded by inflation unless they are inflation-adjusted to keep their real values constant. In many countries, employment contracts, pension benefits, and government entitlements (such as [[social security]]) are tied to a cost-of-living index, typically to the [[consumer price index]].<ref name="cola wars">{{cite web |url=http://www.govexec.com/dailyfed/0906/090806rp.htm |title=COLA Wars |date=September 8, 2006 |work=Government Executive |publisher=[[National Journal Group]] |access-date=September 23, 2008 |last=Flanagan |first=Tammy |archive-url=https://web.archive.org/web/20081005120234/http://www.govexec.com/dailyfed/0906/090806rp.htm |archive-date=October 5, 2008 }}</ref> A ''cost-of-living adjustment'' (COLA) adjusts salaries based on changes in a cost-of-living index.<ref>{{Cite web |last=Kunkel |first=Sue |title=Cost-Of-Living Adjustment (COLA) |url=https://www.ssa.gov/oact/cola/colasummary.html |url-status=live |archive-url=https://web.archive.org/web/20211127155725/https://www.ssa.gov/OACT/COLA/colasummary.html |archive-date=November 27, 2021 |access-date=2018-05-15 |website=www.ssa.gov |language=en-us}}</ref> It does not control inflation, but rather seeks to mitigate the consequences of inflation for those on fixed incomes. Salaries are typically adjusted annually in low inflation economies. During hyperinflation they are adjusted more often.<ref name="cola wars" /> They may also be tied to a cost-of-living index that varies by geographic location if the employee moves.


Annual escalation clauses in employment contracts can specify retroactive or future percentage increases in worker pay which are not tied to any index. These negotiated increases in pay are colloquially referred to as cost-of-living adjustments ("COLAs") or cost-of-living increases because of their similarity to increases tied to externally determined indexes.
Annual escalation clauses in employment contracts can specify retroactive or future percentage increases in worker pay which are not tied to any index. These negotiated increases in pay are colloquially referred to as cost-of-living adjustments ("COLAs") or cost-of-living increases because of their similarity to increases tied to externally determined indexes.


== Controlling inflation ==
== Control of inflation ==
 
[[Monetary policy]] is the policy enacted by the monetary authorities (most frequently the [[central bank]] of a nation) to accomplish their objectives.<ref name="palgrave">Lindsey, D. E.; Wallich, H. C. (2018). "Monetary Policy". In: ''The New Palgrave Dictionary of Economics''. London: Palgrave Macmillan. Retrieved September 17, 2023.</ref> Among these, keeping inflation at a low and stable level is often a prominent objective, either directly via [[inflation targeting]] or indirectly, e.g. via a [[fixed exchange rate]] against a low-inflation currency area.
[[File:Federal Funds Rate (effective).svg|thumb|right|The U.S. effective [[federal funds rate]] charted over fifty years]]
 
===Monetary policy===
{{Main|Monetary policy}}
 
Monetary policy is the policy enacted by the [[monetary authority|monetary authorities]] (most frequently the [[central bank]] of a nation) to control the [[interest rate]]{{snd}}or equivalently the [[money supply]]{{snd}}so as to control inflation and ensure price stability. Higher interest rates reduce the economy's money supply because fewer people seek loans. When banks make loans, the loan proceeds are generally deposited in bank accounts that are part of the money supply, thereby expanding it. When banks make fewer loans, the amount of bank deposits and hence the money supply decrease. For example, in the early 1980s, when the US [[federal funds rate]] exceeded 15%, the quantity of [[Federal Reserve]] dollars fell 8.1%, from US$8.6&nbsp;trillion down to $7.9&nbsp;trillion.
 
In the latter half of the 20th century, there was debate between [[Keynesian]]s and [[monetarist]]s about the appropriate instrument to use to control inflation. Monetarists emphasize a low and steady growth rate of the money supply, while Keynesians emphasize controlling [[aggregate demand]], by reducing demand during economic expansions and increasing demand during recessions to keep inflation stable. Control of aggregate demand can be achieved by using either monetary policy or [[fiscal policy]] (increasing taxation or reducing government spending to reduce demand). Since the 1980s, most countries have primarily relied on monetary policy to control inflation. When inflation exceeds an acceptable level, the country's central bank increases the interest rate, which tends to slow down economic growth and inflation. Some central banks have a [[symmetrical inflation target]], while others only react when inflation rises above a certain threshold.
 
In the 21st century, most economists favor a low and steady rate of inflation. In most countries, central banks or other monetary authorities are tasked with keeping interest rates and prices stable, and inflation near a target rate. These [[Inflation targeting|inflation targets]] may be publicly disclosed or not. In most [[OECD|OECD countries]], the inflation target is usually about 2% to 3% (in developing countries like Armenia, the inflation target is higher, at around 4%).<ref>{{Cite web |title=Inflation Reports |url=https://www.cba.am/en/SitePages/mppubl.aspx |access-date=2022-12-06 |website=www.cba.am |archive-date=December 6, 2022 |archive-url=https://web.archive.org/web/20221206004614/https://www.cba.am/en/SitePages/mppubl.aspx |url-status=live }}</ref> Central banks target a low inflation rate because they believe that high inflation is economically costly because it would create uncertainty about differences in [[relative price]]s and about the inflation rate itself. A low positive inflation rate is targeted rather than a zero or negative one because the latter could cause or worsen [[recession]]s;<ref name="econjournalwatch.org"/> low (as opposed to zero or [[Deflation|negative]]) inflation reduces the severity of economic recessions by enabling the labor market to adjust more quickly in a downturn, and reduces the risk that a [[liquidity trap]] prevents monetary policy from stabilizing the economy.<ref name="aeaweb.org"/>


===Other methods===
=== Historical approaches to inflation control ===
Historically, central banks and governments have followed various policies to achieve low inflation, employing various nominal anchors. Before [[World War I]], the [[gold standard]] was prevalent, but was eventually found to be detrimental to [[economic stability]] and employment, not least during the [[Great Depression]] in the 1930s.<ref name="Historical"/> For the first decades after [[World War II]], the [[Bretton Woods system]] initiated a [[fixed exchange rate system]] for most developed countries, tying their currencies to the US dollar, which again was directly convertible to gold.<ref>{{cite web |title=About the IMF: History: Cooperation and reconstruction (1944–1971) |url=https://www.imf.org/external/about/histcoop.htm |access-date=17 September 2023 |website=www.imf.org}}</ref> The system disintegrated in the 1970s, however, after which the major currencies started floating against each other.<ref>{{cite web |title=About the IMF: History: The end of the Bretton Woods System (1972–1981) |url=https://www.imf.org/external/about/histend.htm |access-date=17 September 2023 |website=www.imf.org}}</ref> During the 1970s many central banks turned to a [[money supply]] target recommended by [[Milton Friedman]] and other [[monetarist]]s, aiming for a stable growth rate of money to control inflation. However, it was found to be impractical because of the unstable relationship between monetary aggregates and other macroeconomic variables, and was eventually abandoned by all major economies.<ref name="Historical">{{cite web |title=Federal Reserve Board – Historical Approaches to Monetary Policy |url=https://www.federalreserve.gov/monetarypolicy/historical-approaches-to-monetary-policy.htm |website=Board of Governors of the Federal Reserve System |access-date=17 September 2023 |language=en |date=8 March 2018}}</ref> In 1990, New Zealand as the first country ever adopted an official [[inflation target]] as the basis of its monetary policy, continually adjusting interest rates to steer the country's inflation rate towards its official target. The strategy was generally considered to work well, and central banks in most [[developed countries]] have over the years adapted a similar strategy.<ref name=Holdingline>{{cite web |title=Inflation Targeting: Holding the Line |url=https://www.imf.org/external/pubs/ft/fandd/basics/72-inflation-targeting.htm |website=www.imf.org |access-date=17 September 2023}}</ref> As of 2023, the central banks of all [[G7]] member countries can be said to follow an inflation target, including the [[European Central Bank]] and the [[Federal Reserve]], who have adopted the main elements of inflation targeting without officially calling themselves inflation targeters.<ref name=Holdingline/> In emerging countries fixed exchange rate regimes are still the most common monetary policy.<ref name=IMF>{{cite book |last1=Department |first1=International Monetary Fund Monetary and Capital Markets |title=Annual Report on Exchange Arrangements and Exchange Restrictions 2022 |date=2023 |publisher=International Monetary Fund |isbn=979-8-4002-3526-9 |url=https://www.elibrary.imf.org/display/book/9798400235269/9798400235269.xml?code=imf.org |access-date=12 August 2023 |language=en }}</ref>


==== Fixed exchange rates ====
=== Fixed exchange rates ===
{{Main|Fixed exchange rate system}}


{{Main|Fixed exchange rate}}
Under a fixed exchange rate currency regime, a country's currency is tied in value to another single currency or to a basket of other currencies. A fixed exchange rate is usually used to stabilize the value of a currency, vis-a-vis the currency it is pegged to. It can also be used as a means to control inflation if the currency area tied to itself maintains low and stable inflation. However, as the value of the reference currency rises and falls, so does the currency pegged to it. This essentially means that the inflation rate in the fixed exchange rate country is determined by the inflation rate of the country the currency is pegged to. In addition, a fixed exchange rate prevents a government from using domestic monetary policy to achieve macroeconomic stability.<ref>{{cite book |last1=Blanchard |first1=Olivier |title=Macroeconomics: a European perspective |last2=Amighini |first2=Alessia |last3=Giavazzi |first3=Francesco |date=2017 |publisher=Pearson |isbn=978-1-292-08567-8 |edition=3rd |location=Harlow, London, New York, Boston, San Francisco, Toronto, Sydney, Dubai, Singapore, Hong Kong, Tokyo, Seoul, Taipei, New Delhi, Cape Town, Sao Paulo, Mexico City, Madrid, Amsterdam, Munich, Paris, Milan |chapter=Output, the interest rate and the exchange rate}}</ref>
Under a fixed exchange rate currency regime, a country's currency is tied in value to another single currency or to a basket of other currencies (or sometimes to another measure of value, such as gold). A fixed exchange rate is usually used to stabilize the value of a currency, vis-a-vis the currency it is pegged to. It can also be used as a means to control inflation. However, as the value of the reference currency rises and falls, so does the currency pegged to it. This essentially means that the inflation rate in the fixed exchange rate country is determined by the inflation rate of the country the currency is pegged to. In addition, a fixed exchange rate prevents a government from using domestic monetary policy to achieve macroeconomic stability.


Under the [[Bretton Woods system|Bretton Woods]] agreement, most countries around the world had currencies that were fixed to the U.S. dollar. This limited inflation in those countries, but also exposed them to the danger of [[speculative attack]]s. After the Bretton Woods agreement broke down in the early 1970s, countries gradually turned to [[floating exchange rates]]. However, in the later part of the 20th century, some countries reverted to a fixed exchange rate as part of an attempt to control inflation. This policy of using a fixed exchange rate to control inflation was used in many countries in South America in the later part of the 20th century (e.g. [[Argentine Currency Board|Argentina (1991–2002)]], Bolivia, Brazil, Chile, etc.). <!-- Information needed on other countries where fixed exchange rate regimes have also been tried -->
As of 2023, [[Denmark]] is the only [[OECD]] country which maintains a fixed exchange rate (against the [[euro]]), but it is frequently used as a monetary policy strategy in developing countries.<ref name=IMF/>
 
==== Gold standard ====


===Gold standard===
{{Main|Gold standard}}
{{Main|Gold standard}}
[[File:Two 20kr gold coins.png|thumb|right|Two 20 [[Swedish krona|krona]] gold coins from the [[Scandinavian Monetary Union]], a historical example of an international gold standard]]


The gold standard is a monetary system in which a region's common medium of exchange is paper notes (or other monetary token) that are normally freely convertible into pre-set, fixed quantities of gold. The standard specifies how the gold backing would be implemented, including the amount of [[Bullion coin|specie]] per currency unit. The currency itself has no ''innate value'', but is accepted by traders because it can be redeemed for the equivalent specie. A [[Silver certificate (United States)|U.S. silver certificate]], for example, could be redeemed for an actual piece of silver.
[[File:Two 20kr gold coins.png|thumb|right|upright=1.2|Two 20 [[Swedish krona|krona]] gold coins from the [[Scandinavian Monetary Union]], a historical example of an international gold standard]]


The gold standard was partially abandoned via the international adoption of the [[Bretton Woods system]]. Under this system all other major currencies were tied at fixed rates to the US dollar, which itself was tied by the US government to gold at the rate of US$35 per ounce. The Bretton Woods system broke down in 1971, causing most countries to switch to [[fiat currency|fiat money]]{{snd}} money backed only by the laws of the country.
The gold standard is a monetary system in which a region's common medium of exchange is paper notes (or other monetary token) that are normally freely convertible into pre-set, fixed quantities of gold. The standard specifies how the gold backing would be implemented, including the amount of [[Bullion coin|specie]] per currency unit. The currency itself has no ''innate value'' but is accepted by traders because it can be redeemed for the equivalent value of the commodity (specie). A [[Silver certificate (United States)|U.S. silver certificate]], for example, could be redeemed for an actual piece of silver.


Under a gold standard, the long term rate of inflation (or deflation) would be determined by the growth rate of the supply of gold relative to total output.<ref>{{cite encyclopedia|last =Bordo|first =Michael D.|date =2002|url =http://www.econlib.org/library/Enc/GoldStandard.html|title =Gold Standard|encyclopedia =The Concise Encyclopedia of Economics|publisher =Library of Economics and Liberty|access-date =September 23, 2008|archive-date =October 5, 2010|archive-url =https://web.archive.org/web/20101005063134/http://www.econlib.org/library/Enc/GoldStandard.html|url-status =live}}</ref> Critics argue that this will cause arbitrary fluctuations in the inflation rate, and that monetary policy would essentially be determined by gold mining.<ref name="BarskyDeLong">{{cite journal |last1=Barsky |first1=Robert B |first2=J Bradford |last2=DeLong |year=1991 |title=Forecasting Pre-World War I Inflation: The Fisher Effect and the Gold Standard |journal=Quarterly Journal of Economics |volume=106 |issue=3 |pages=815–836 |url=https://ideas.repec.org/a/tpr/qjecon/v106y1991i3p815-36.html |access-date=September 27, 2008 |doi=10.2307/2937928 |jstor=2937928 |archive-date=June 20, 2015 |archive-url=https://web.archive.org/web/20150620163911/https://ideas.repec.org/a/tpr/qjecon/v106y1991i3p815-36.html |url-status=live }}</ref><ref name="DeLong">{{cite web |url=http://www.j-bradford-delong.net/Politics/whynotthegoldstandard.html |title=Why Not the Gold Standard? |last=DeLong |first=Brad |access-date=September 25, 2008 |archive-url=https://web.archive.org/web/20101018035441/http://www.j-bradford-delong.net/politics/whynotthegoldstandard.html |archive-date=October 18, 2010 |url-status=dead }}</ref>
Under a gold standard, the long term rate of inflation (or deflation) would be determined by the growth rate of the supply of gold relative to total output.<ref>{{cite encyclopedia|last =Bordo|first =Michael D.|date =2002|url =http://www.econlib.org/library/Enc/GoldStandard.html|title =Gold Standard|encyclopedia =The Concise Encyclopedia of Economics|publisher =Library of Economics and Liberty|access-date =September 23, 2008|archive-date =October 5, 2010|archive-url =https://web.archive.org/web/20101005063134/http://www.econlib.org/library/Enc/GoldStandard.html|url-status =live}}</ref> Critics argue that this will cause arbitrary fluctuations in the inflation rate, and that monetary policy would essentially be determined by an intersection of however much new gold was produced by mining and changing demand for gold for practical uses.<ref>{{cite journal |last1=Barsky |first1=Robert B. |last2=DeLong |first2=J. Bradford |year=1991 |title=Forecasting Pre-World War I Inflation: The Fisher Effect and the Gold Standard |url=https://ideas.repec.org/a/tpr/qjecon/v106y1991i3p815-36.html |url-status=live |journal=Quarterly Journal of Economics |volume=106 |issue=3 |pages=815–836 |doi=10.2307/2937928 |jstor=2937928 |archive-url=https://web.archive.org/web/20150620163911/https://ideas.repec.org/a/tpr/qjecon/v106y1991i3p815-36.html |archive-date=June 20, 2015 |access-date=September 27, 2008|url-access=subscription }}</ref><ref>{{cite web |url=http://www.j-bradford-delong.net/Politics/whynotthegoldstandard.html |title=Why Not the Gold Standard? |last=DeLong |first=Brad |access-date=September 25, 2008 |archive-url=https://web.archive.org/web/20101018035441/http://www.j-bradford-delong.net/politics/whynotthegoldstandard.html |archive-date=October 18, 2010 }}</ref> The gold standard was historically found to make it more difficult to stabilize employment levels and avoid recessions and was eventually abandoned everywhere.<ref name="Historical"/><ref>{{cite web |last=Abdel-Monem |first=Tarik |title=What is The Gold Standard? |url=http://www.uiowa.edu/ifdebook/faq/faq_docs/gold_standard.shtml |publisher=University of Iowa Center for The Center for International Finance and Development |archive-url=https://web.archive.org/web/20091121143147/http://www.uiowa.edu/ifdebook/faq/faq_docs/gold_standard.shtml |archive-date=2009-11-21 }}</ref>


==== Wage and price controls ====
===Demurrage currency===
[[Freiwirtschaft]] economists theorize that [[demurrage currency]] could eliminate both inflation and deflation. There tends to be some interest cost that is built into the goods and services that consumers tend to purchase,<ref name="lietaer-1990">{{cite journal |last=Lietaer |first=Bernard A. |date=July 1990 |title=A Strategy for a Convertible Currency |url=https://folk.ntnu.no/tronda/finans/others/interest-free-money-formatted.pdf |journal=ICIS Forum |volume=20 |issue=3 |publisher=International Center for Integrative Studies |access-date=4 May 2025}}</ref>{{rp|p=4}} so if demurrage currency eliminates interest rates, then prices are less likely to increase. Demurrage would also naturally cause the money supply to decrease, thus causing deflation. If a central bank issues and monitors demurrage currency as Gesell originally proposed, then it could replace all the money that disappears due to demurrage by printing money at a similar rate.<ref name="baynham-2023">{{cite journal |url=https://www.noemamag.com/what-if-money-expired/ |title=What If Money Expired? |last=Baynham |first=Jacob |date=14 November 2023 |website=Noema Magazine |publisher=Berggruen Institute |access-date=26 April 2025}}</ref> The money printing could create just enough inflation to cancel out the natural deflation of demurrage, thus achieving an [[inflation target]] of 0%.<ref name="sidman-lecture-6-inflation">{{cite AV media |last=Sidman |first=Josh |date=3 April 2024 |title="Silvio Gesell: Beyond Capitalism vs Socialism" Class #6 |url=https://www.youtube.com/watch?v=1GjX4PCcTlU?t=918 |time=15:18 |type=Video |language=English |publisher=Henry George School of Economics |access-date=23 May 2025}}</ref>


===Wage and price controls===
{{See also|Incomes policy}}
{{See also|Incomes policy}}
Another method attempted in the past have been wage and [[price controls]] ("incomes policies"). Temporary price controls may be used as a complement to other policies to fight inflation; price controls may make disinflation faster, while reducing the need for unemployment to reduce inflation. If price controls are used during a recession, the kinds of distortions that price controls cause may be lessened. However, economists generally advise against the imposition of price controls {{cn}}.
Another method attempted in the past have been wage and [[price controls]] ("incomes policies"). Temporary price controls may be used as a complement to other policies to fight inflation; price controls may make disinflation faster, while reducing the need for unemployment to reduce inflation. If price controls are used during a recession, the kinds of distortions that price controls cause may be lessened. However, economists generally advise against the imposition of price controls.<ref>{{Cite web |date=2022-03-24 |title=Why Price Controls Should Stay in the History Books |url=https://www.stlouisfed.org/publications/regional-economist/2022/mar/why-price-controls-should-stay-history-books |access-date=2024-09-05 |website=www.stlouisfed.org |language=en}}</ref><ref>{{Cite web |last=n.a. |date=2022-09-27 |title=The Economics of Price Controls |url=https://www.jec.senate.gov/public/index.cfm/republicans/2022/9/the-economics-of-price-controls |access-date=2024-09-05 |website=United States Joint Economic Committee |language=en}}</ref><ref>{{Cite web |date=2022-01-20 |title=Price Controls: Still A Bad Idea |url=https://www.hoover.org/research/price-controls-still-bad-idea |access-date=2024-09-05 |website=Hoover Institution |language=en}}</ref>


Wage and price controls, in combination with rationing, have been used successfully in wartime environments. However, their use in other contexts is far more mixed. Notable failures of their use include [[Nixon shock|the 1972 imposition of wage and price controls]] by [[Richard Nixon]]. More successful examples include the [[The Accord|Prices and Incomes Accord]] in Australia and the [[Wassenaar Agreement]] in the [[Netherlands]].
Wage and price controls, in combination with rationing, have been used successfully in wartime environments. However, their use in other contexts is far more mixed. Notable failures of their use include [[Nixon shock|the 1972 imposition of wage and price controls]] by [[Richard Nixon]]. More successful examples include the [[The Accord|Prices and Incomes Accord]] in Australia and the [[Wassenaar Agreement]] in the [[Netherlands]].


In general, wage and price controls are regarded as a temporary and exceptional measures, only effective when coupled with policies designed to reduce the underlying causes of inflation during the [[Wage and price controls|wage and price]] control regime, for example, winning the war being fought. They often have perverse effects, due to the distorted signals they send to the market {{cn}}. Artificially low prices often cause rationing and shortages and discourage future investment, resulting in yet further shortages {{cn}}. The usual economic analysis is that any product or service that is under-priced is overconsumed {{cn}}. For example, if the official price of bread is too low, there will be too little bread at official prices, and too little investment in bread making by the market to satisfy future needs, thereby exacerbating the problem in the long term.
In general, wage and price controls are regarded as a temporary and exceptional measures, only effective when coupled with policies designed to reduce the underlying causes of inflation during the [[Wage and price controls|wage and price]] control regime, for example, winning the war being fought.


== See also ==
=== Inflation targeting ===
{{Main|Inflation targeting}}


From its first inception in New Zealand in 1990, direct inflation targeting as a monetary policy strategy has spread to become prevalent among developed countries. The basic idea is that the central bank perpetually adjusts the [[bank rate]] to influence the country's inflation rate towards its official target. Changes in [[interest rate]]s affect [[aggregate demand]], [[aggregate supply]] and inflation in various ways, also called the [[monetary transmission mechanism]].<ref>{{cite web |title=Federal Reserve Board – Monetary Policy: What Are Its Goals? How Does It Work? |url=https://www.federalreserve.gov/monetarypolicy/monetary-policy-what-are-its-goals-how-does-it-work.htm |website=Board of Governors of the Federal Reserve System |access-date=17 September 2023 |language=en |date=July 29, 2021}}</ref> The relation between [[unemployment]] and inflation is known as the [[Phillips curve]].
In most [[OECD|OECD countries]], the inflation target is about 2%.<ref>{{Cite web |title=Inflation Reports |url=https://www.cba.am/en/SitePages/mppubl.aspx |access-date=2022-12-06 |website=www.cba.am |archive-date=December 6, 2022 |archive-url=https://web.archive.org/web/20221206004614/https://www.cba.am/en/SitePages/mppubl.aspx |url-status=live }}</ref> Citizens show generally a high aversion to inflation.<ref name="z877">{{cite journal | last1=Binetti | first1=Alberto | last2=Nuzzi | first2=Francesco | last3=Stantcheva | first3=Stefanie | title=People's understanding of inflation | journal=Journal of Monetary Economics | volume=148 | date=2024 | doi=10.1016/j.jmoneco.2024.103652 | doi-access=free | article-number=103652}}</ref> On average voters prefer an inflation rate around 0%.<ref>{{Citation|title=Inflation Preferences|url=https://www.nber.org/papers/w32379|publisher=National Bureau of Economic Research|date=2024|access-date=2026-01-31|id=32379|series=Working Paper Series|type=Working Paper|doi=10.3386/w32379|first=Hassan|last=Afrouzi|first2=Alexander|last2=Dietrich|first3=Kristian|last3=Myrseth|first4=Romanos|last4=Priftis|first5=Raphael|last5=Schoenle|doi-access=free}}</ref>
==See also==
{{cols|colwidth=21em}}
{{cols|colwidth=21em}}
* [[Artificial scarcity]]
* [[Core inflation]]
* [[Core inflation]]
* [[Cost of living]]
* [[Cumulative process]]
* [[Fisher equation]]
* [[Food prices]]
* [[Food prices]]
* [[Hyperinflation]]
* [[Hyperinflation]]
* [[Indexed unit of account]]
* [[Indexed unit of account]]
* [[Inflationism]]
* [[Inflationism]]
* [[Inflation accounting]]
* [[Inflation beta]]
* [[Inflation derivative]]
* [[Inflation hedge]]
* [[Inflation hedge]]
* [[Headline inflation]]
* [[Headline inflation]]
* [[List of countries by inflation rate]]
* [[Measuring economic worth over time]]
* [[Measuring economic worth over time]]
* [[Overconsumption]]
* [[Overconsumption]]
* [[Real versus nominal value (economics)]]
* [[Shrinkflation]] and [[Skimpflation]]
* [[Shrinkflation]] and [[Skimpflation]]
* [[Real versus nominal value (economics)]]
* [[Secular inflation]]
* [[Steady-state economy]]
* [[Steady-state economy]]
* [[Stealth inflation]]
* [[Supply shock]]
* [[Welfare cost of inflation]]
* [[Welfare cost of inflation]]
* [[Supply shock]]
* [[Template:Inflation]] – for price conversions in Bharatpedia articles
{{colend}}
{{colend}}


== Notes ==
==References==
 
{{Reflist}}
{{Reflist|30em}}
 
== References ==
 
* {{Cite book |last1=Abel |first1=Andrew B. |last2=Bernanke |first2=Ben S. |last3=Croushore |first3=Dean |author-link1=Andrew Abel|author-link2=Ben Bernanke |title=Macroeconomics |publisher=Pearson |year=2005 |edition=5th |isbn=978-0-32119963-8}} Measurement of inflation is discussed in Ch. 2, pp.&nbsp;45–50; Money growth & Inflation in Ch. 7, pp.&nbsp;266–269; Keynesian business cycles and inflation in Ch. 9, pp.&nbsp;308–348.
* {{Cite book |last1=Abel |first1=Andrew B. |last2=Bernanke |first2=Ben S. |last3=Croushore |first3=Dean |author-link1=Andrew Abel|author-link2=Ben Bernanke |title=Macroeconomics |publisher=Pearson |year=2005 |edition=5th |isbn=978-0-32119963-8}} Measurement of inflation is discussed in Ch. 2, pp.&nbsp;45–50; Money growth & Inflation in Ch. 7, pp.&nbsp;266–269; Keynesian business cycles and inflation in Ch. 9, pp.&nbsp;308–348.
* {{Cite book |last=Barro |first=Robert J. |author-link =Robert Barro |title=Macroeconomics |publisher=MIT Press |location=Cambridge, MA. |year=1997 |page= 895 |isbn=0-262-02436-5 }}
* {{Cite book |last=Barro |first=Robert J. |author-link=Robert Barro |title=Macroeconomics |publisher=MIT Press |location=Cambridge, Massachusetts |year=1997 |page=895 |language=en-us |isbn=0-262-02436-5}}
* {{Cite book |last=Blanchard |first=Olivier |author-link=Olivier Blanchard |title=Macroeconomics |publisher=Prentice Hall |location=Englewood Cliffs, N.J. |year=2000 |isbn=0-13-013306-X |edition=2nd }}
* {{cite book |last=Blanchard |first=Olivier |author-link=Olivier Blanchard |title=Macroeconomics |date=2021 |publisher=Pearson |location=Harlow, England |isbn=978-0-134-89789-9 |edition=Eighth, global}}
* {{Cite book |last1=Burda |first1=Michael C. |author-link=Michael C. Burda |last2=Wyplosz |first2=Charles |title=Macroeconomics: a European text |publisher=[[Oxford University Press]] |location=Oxford [Oxfordshire] |year=1997 |isbn=0-19-877468-0 }}
* {{Cite book |last1=Hall |first1=Robert E. |author-link=Robert Hall (economist) |last2=Taylor |first2=John B. |author-link2=John B. Taylor |title=Macroeconomics |publisher=W.W. Norton |location=New York |year=1993 |page=[https://archive.org/details/macroeconomics00hall/page/637 637] |isbn=0-393-96307-1 |url-access=registration |url=https://archive.org/details/macroeconomics00hall/page/637 }}
* {{Cite book |last=Mankiw |first=N. Gregory |author-link=Greg Mankiw |title=Macroeconomics |publisher=Worth |year=2002 |edition=5th |isbn=978-0-71675237-0}} Measurement of inflation is discussed in Ch. 2, pp.&nbsp;22–32; Money growth & Inflation in Ch. 4, pp.&nbsp;81–107; Keynesian business cycles and inflation in Ch. 9, pp.&nbsp;238–255.
* {{Cite book |last=Mankiw |first=N. Gregory |author-link=Greg Mankiw |title=Macroeconomics |publisher=Worth |year=2002 |edition=5th |isbn=978-0-71675237-0}} Measurement of inflation is discussed in Ch. 2, pp.&nbsp;22–32; Money growth & Inflation in Ch. 4, pp.&nbsp;81–107; Keynesian business cycles and inflation in Ch. 9, pp.&nbsp;238–255.
* {{Cite book |last1=Hall |first1=Robert E. |author-link=Robert Hall (economist) |last2=Taylor |first2=John B. |author-link2=John B. Taylor |title=Macroeconomics |publisher=W.W. Norton |location=New York |year=1993 |page=[https://archive.org/details/macroeconomics00hall/page/637 637] |isbn=0-393-96307-1 |url-access=registration |url=https://archive.org/details/macroeconomics00hall/page/637 }}
* {{cite book |last1=Romer |first1=David |author-link=David Romer |title=Advanced macroeconomics |date=2019 |publisher=McGraw-Hill |location=New York, NY |isbn=978-1-260-18521-8 |edition=Fifth}}
* {{Cite book |last1=Burda |first1=Michael C. |author-link=Michael C. Burda |last2=Wyplosz |first2=Charles |title=Macroeconomics: a European text |publisher=[[Oxford University Press]] |location=Oxford [Oxfordshire] |year=1997 |isbn=0-19-877468-0 }}


== Further reading ==
== Further reading ==
* [[Leonardo Auernheimer|Auernheimer, Leonardo]], "The Honest Government's Guide to the Revenue From the Creation of Money", Journal of Political Economy, Vol. 82, No. 3, May/June 1974, pp.&nbsp;598–606.
* [[William Baumol|Baumol, William J.]] and [[Alan S. Blinder]], ''Macroeconomics: Principles and Policy'', Tenth edition. Thomson South-Western, 2006. {{ISBN|0-324-22114-2}}.
* [[Federal Reserve Bank of Boston]], [http://www.bos.frb.org/economic/conf/conf53/index.htm "Understanding Inflation and the Implications for Monetary Policy: A Phillips Curve Retrospective"] {{Webarchive|url=https://web.archive.org/web/20130826003309/http://www.bos.frb.org/economic/conf/conf53/index.htm |date=August 26, 2013 }}, Conference Series 53, June 9–11, 2008, Chatham, Massachusetts. (Also cf. [[Phillips curve]] article).
* [[Milton Friedman|Friedman, Milton]], Nobel lecture: [https://www.nobelprize.org/nobel_prizes/economics/laureates/1976/friedman-lecture.pdf Inflation and unemployment] 1977.
* [[Frederic Mishkin|Mishkin, Frederic S.]], ''The Economics of Money, Banking, and Financial Markets'', New York, HarperCollins, 1995.
* [[World Bank]], 2018. [https://www.worldbank.org/en/research/publication/inflation-in-emerging-and-developing-economies ''Inflation in Emerging and Developing Economies: Evolution, Drivers and Policies'']. Edited by Jongrim Ha, M. Ayhan Kose, and Franziska Ohnsorge.


* World Bank, 2018. [https://www.worldbank.org/en/research/publication/inflation-in-emerging-and-developing-economies ''Inflation in Emerging and Developing Economies: Evolution, Drivers and Policies'']. Edited by Jongrim Ha, M. Ayhan Kose, and Franziska Ohnsorge.
==External links==
* [[Leonardo Auernheimer|Auernheimer, Leonardo]], "The Honest Government's Guide to the Revenue From the Creation of Money," Journal of Political Economy, Vol. 82, No. 3, May/June 1974, pp.&nbsp;598–606.
{{wikiquote}}
* [[William Baumol|Baumol, William J.]] and [[Alan S. Blinder]], ''Macroeconomics: Principles and Policy'', Tenth edition. Thomson South-Western, 2006. {{ISBN|0-324-22114-2}}
* [[Milton Friedman|Friedman, Milton]], Nobel lecture: [https://www.nobelprize.org/nobel_prizes/economics/laureates/1976/friedman-lecture.pdf Inflation and unemployment] 1977
* [[Frederic Mishkin|Mishkin, Frederic S.]], ''The Economics of Money, Banking, and Financial Markets'', New York, Harper Collins, 1995.
* [[Federal Reserve Bank of Boston]], [http://www.bos.frb.org/economic/conf/conf53/index.htm "Understanding Inflation and the Implications for Monetary Policy: A Phillips Curve Retrospective"] {{Webarchive|url=https://web.archive.org/web/20130826003309/http://www.bos.frb.org/economic/conf/conf53/index.htm }}, Conference Series 53, June 9–11, 2008, Chatham, Massachusetts. (Also cf. [[Phillips curve]] article)
 
== External links ==
{{Library resources box
{{Library resources box
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* [https://data.oecd.org/price/inflation-cpi.htm OECD Consumer Price Index]
* [https://data.worldbank.org/indicator/FP.CPI.TOTL.ZG World Bank annual inflation rates for all countries]
* [http://www.bls.gov/cpi/ United States Bureau of Labor Statistics – Consumer Price Index]
* [https://calcinflation.com/ Inflation Calculator]
* [http://dailytools.in/FinanceInvestment/InflationCalculator General purpose compounded inflation calculator]
* [http://dailytools.in/FinanceInvestment/InflationCalculator General purpose compounded inflation calculator]
* [http://www.aier.org/cost-living-calculator U.S. Cost of Living Calculator (1913–present)] ([[American Institute for Economic Research|AIER]])
* [[Consumer price index|Consumer Price Indexes]]
* [http://www.bls.gov/data/inflation_calculator.htm U.S. Inflation Calculator (1913–present)] ([[US Bureau of Labor Statistics|US BLS]])
** [https://data.oecd.org/price/inflation-cpi.htm OECD]
* [https://fraser.stlouisfed.org/theme/59 U.S. Inflation (historical documents)] ([[Federal Reserve Economic Data#Other Federal Reserve Bank of St. Louis data services|FRASER]])
** [http://www.bls.gov/cpi/ United States] ([[Bureau of Labor Statistics]])
* [https://web.archive.org/web/20080422012228/http://www.riksbank.com/templates/Page.aspx?id=27404 World Inflation (1290–2006)] ([[Consumer Price Index]]) ([[Swedish Riksbank]])
** [https://web.archive.org/web/20080422012228/http://www.riksbank.com/templates/Page.aspx?id=27404 World Inflation (1290–2006)] ([[Swedish Riksbank]])
* [https://data.worldbank.org/indicator/FP.CPI.TOTL.ZG World Bank annual inflation rates for all countries]
* US-specific
** [http://www.aier.org/cost-living-calculator Cost of Living Calculator (1913–present)] {{Webarchive|url=https://web.archive.org/web/20190905192854/http://www.aier.org/cost-living-calculator |date=September 5, 2019 }} ([[American Institute for Economic Research|AIER]])
** [http://www.bls.gov/data/inflation_calculator.htm Inflation Calculator (1913–present)] ([[US Bureau of Labor Statistics|US BLS]])
** [https://fraser.stlouisfed.org/theme/59 Inflation (historical documents)] ([[Federal Reserve Economic Data#Other Federal Reserve Bank of St. Louis data services|FRASER]])


{{Economics}}
{{Economics}}
{{United States – Commonwealth of Nations recessions}}
{{United States – Commonwealth of Nations recessions}}
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[[Category:Inflation| ]]
[[Category:Inflation| ]]

Latest revision as of 21:33, 10 March 2026


Template:Macroeconomics sidebar

Global rates of inflation in October 2025 among International Monetary Fund members
UK and US monthly inflation rates from January 1989[1][2]

In economics, inflation is an increase in the average price of goods and services in terms of money.[3][4]:579 This increase is measured using a price index, typically a consumer price index (CPI).[5][6][7][8] When the general price level rises, each unit of currency buys fewer goods and services; consequently, inflation corresponds to a reduction in the purchasing power of money.[9][10] The opposite of inflation is deflation, a decrease in the general price level of goods and services. The common measure of inflation is the inflation rate, the annualized percentage change in a general price index.[11]:22–32

Changes in inflation are widely attributed to increases in the money supply, fluctuations in real demand for goods and services (also known as demand shocks, including changes in fiscal or monetary policy), changes in available supplies such as during energy crises (also known as supply shocks), significant decreases in interest rates set by the central bank, or changes in inflation expectations, which may be self-fulfilling.[4][12] Moderate inflation affects economies in both positive and negative ways. The negative effects would include an increase in the opportunity cost of holding money; uncertainty over future inflation, which may discourage investment and savings; and, if inflation were rapid enough, shortages of goods as consumers begin hoarding out of concern that prices will increase in the future. Positive effects include reducing unemployment due to nominal wage rigidity,[11]:238–255 allowing the central bank greater freedom in carrying out monetary policy, encouraging loans and investment instead of money hoarding, and avoiding the inefficiencies associated with deflation.

Today, most economists favour a low and steady rate of inflation. Low (as opposed to zero or negative) inflation reduces the likelihood of economic recessions by enabling the labor market to adjust more quickly and reduces the risk that a liquidity trap prevents monetary policy from stabilizing the economy, while also avoiding the costs associated with high inflation.[13] The task of keeping the rate of inflation low and stable is usually given to central banks that control monetary policy, normally through the setting of interest rates and by carrying out open market operations.[12]

Terminology[edit | edit source]

The term originates from the Latin inflare (to blow into or inflate). Conceptually, inflation refers to the general trend of prices, not changes in any specific price. For example, if people choose to buy more cucumbers than tomatoes, cucumbers consequently become more expensive and tomatoes less expensive. These changes are not related to inflation; they reflect a shift in tastes. Inflation is related to the value of currency itself. When currency was linked with gold, if new gold deposits were found, the price of gold and the value of currency would fall, and consequently, the prices of all other goods would become higher.[14]

Classical economics[edit | edit source]

By the nineteenth century, economists categorised three separate factors that cause a rise or fall in the price of goods: a change in the value or production costs of the good, a change in the price of money which then was usually a fluctuation in the commodity price of the metallic content in the currency, and currency depreciation resulting from an increased supply of currency relative to the quantity of redeemable metal backing the currency. Following the proliferation of private banknote currency printed during the American Civil War, the term "inflation" started to appear as a direct reference to the currency depreciation that occurred as the quantity of redeemable banknotes outstripped the quantity of metal available for their redemption. At that time, the term inflation referred to the devaluation of the currency, and not to a rise in the price of goods.[15] This relationship between the over-supply of banknotes and a resulting depreciation in their value was noted by earlier classical economists such as David Hume and David Ricardo, who would go on to examine and debate what effect a currency devaluation has on the price of goods.[16]

Related concepts[edit | edit source]

Other economic concepts related to inflation include: deflation – a fall in the general price level;[17] disinflation – a decrease in the rate of inflation;[18] hyperinflation – an out-of-control inflationary spiral;[19] stagflation – a combination of inflation, slow economic growth and high unemployment;[20] reflation – an attempt to raise the general level of prices to counteract deflationary pressures;[21] asset price inflation – a general rise in the prices of financial assets without a corresponding increase in the prices of goods or services;[22] and agflation – an advanced increase in the price for food and industrial agricultural crops when compared with the general rise in prices.[23]

More specific forms of inflation refer to sectors whose prices vary semi-independently from the general trend. "House price inflation" applies to changes in the house price index[24] while "energy inflation" is dominated by the costs of oil and gas.[25]

History[edit | edit source]

US historical inflation (in blue) and deflation (in green) from the mid-17th century to the beginning of the 21st

Overview[edit | edit source]

Inflation has been a feature of history during the entire period when money has been used as a means of payment. One of the earliest documented inflations occurred in Alexander the Great's empire 330 BC.[26] Historically, when commodity money was used, periods of inflation and deflation would alternate depending on the condition of the economy. However, when large, prolonged infusions of gold or silver into an economy occurred, this could lead to long periods of inflation.

The adoption of fiat currency by many countries, from the 18th century onwards, made much larger variations in the supply of money possible.[27] Rapid increases in the money supply have taken place a number of times in countries experiencing political crises, producing hyperinflations – episodes of extreme inflation rates much higher than those observed in earlier periods of commodity money. The hyperinflation in the Weimar Republic of Germany is a notable example. The hyperinflation in Venezuela is the highest in the world, with an annual inflation rate of 833,997% as of October 2018.[28]

Historically, inflations of varying magnitudes have occurred, interspersed with corresponding deflationary periods,[26] from the price revolution of the 16th century, which was driven by the flood of gold and particularly silver seized and mined by the Spaniards in Latin America, to the largest paper money inflation of all time in Hungary after World War II.[29]

However, since the 1980s, inflation has been held low and stable in countries with independent central banks. This has led to a moderation of the business cycle and a reduction in variation in most macroeconomic indicators – an event known as the Great Moderation.[30]

Silver purity through time in early Roman imperial silver coins. To increase the number of silver coins in circulation while short on silver, the Roman imperial government repeatedly debased the coins. They melted relatively pure silver coins and then struck new silver coins of lower purity but of nominally equal value. Silver coins were relatively pure before Nero (AD 54–68), but by the 270s had hardly any silver left.
The silver content of Roman silver coins rapidly declined during the Crisis of the Third Century.

Ancient Europe[edit | edit source]

Alexander the Great's conquest of the Persian Empire in 330 BC was followed by one of the earliest documented inflation periods in the ancient world.[26] Rapid increases in the quantity of money or in the overall money supply have occurred in many different societies throughout history, changing with different forms of money used.[31][32] For instance, when silver was used as currency, the government could collect silver coins, melt them down, mix them with other, less valuable metals such as copper or lead and reissue them at the same nominal value, a process known as debasement. At the ascent of Nero as Roman emperor in AD 54, the denarius contained more than 90% silver, but by the 270s hardly any silver was left. By diluting the silver with other metals, the government could issue more coins without increasing the amount of silver used to make them. When the cost of each coin is lowered in this way, the government profits from an increase in seigniorage.[33] This practice would increase the money supply but at the same time the relative value of each coin would be lowered. As the relative value of the coins becomes lower, consumers would need to give more coins in exchange for the same goods and services as before. These goods and services would experience a price increase as the value of each coin is reduced.[34] Again at the end of the third century AD during the reign of Diocletian, the Roman Empire experienced rapid inflation.[26]

Ancient China[edit | edit source]

Song dynasty China introduced the practice of printing paper money to create fiat currency.[35] During the Mongol Yuan dynasty, the government spent a great deal of money fighting costly wars, and reacted by printing more money, leading to inflation.[36] Fearing the inflation that plagued the Yuan dynasty, the Ming dynasty initially rejected the use of paper money, and reverted to using copper coins.[37]

Medieval Egypt[edit | edit source]

During the Malian king Mansa Musa's hajj to Mecca in 1324, he was reportedly accompanied by a camel train that included thousands of people and nearly a hundred camels. When he passed through Cairo, he spent or gave away so much gold that it depressed its price in Egypt for over a decade,[38] reducing its purchasing power. A contemporary Arab historian remarked about Mansa Musa's visit:

Gold was at a high price in Egypt until they came in that year. The mithqal did not go below 25 dirhams and was generally above, but from that time its value fell and it cheapened in price and has remained cheap till now. The mithqal does not exceed 22 dirhams or less. This has been the state of affairs for about twelve years until this day by reason of the large amount of gold which they brought into Egypt and spent there [...].

— Chihab Al-Umari, Kingdom of Mali[39]

Medieval age and "price revolution" in Western Europe[edit | edit source]

There is no reliable evidence of inflation in Europe for the thousand years that followed the fall of the Roman Empire, but from the Middle Ages onwards reliable data do exist. Mostly, the medieval inflation episodes were modest, and there was a tendency for inflationary periods to be followed by deflationary periods.[26]

From the second half of the 15th century to the first half of the 17th, Western Europe experienced a major inflationary cycle referred to as the "price revolution",[40][41] with prices on average rising perhaps sixfold over 150 years. This is often attributed to the influx of gold and silver from the New World into Habsburg Spain,[42] with wider availability of silver in previously cash-starved Europe causing widespread inflation.[43][44] European population rebound from the Black Death began before the arrival of New World metal, and may have begun a process of inflation that New World silver compounded later in the 16th century.[45]

After 1700[edit | edit source]

The U.S. effective federal funds rate charted over fifty years

A pattern of intermittent inflation and deflation periods persisted for centuries until the Great Depression in the 1930s, which was characterized by major deflation. Since the Great Depression, however, there has been a general tendency for prices to rise every year. In the 1970s and early 1980s, annual inflation in most industrialized countries reached two digits (ten percent or more). The double-digit inflation era was of short duration, however, inflation by the mid-1980s returned to more modest levels. Amid this, general trends there have been spectacular high-inflation episodes in individual countries in interwar Europe, towards the end of the Nationalist Chinese government in 1948–1949, and later in some Latin American countries, in Israel, and in Zimbabwe. Some of these episodes are considered hyperinflation periods, normally designating inflation rates that surpass 50 percent monthly.[26]

Measures[edit | edit source]

PPI is a leading indicator, CPI and PCE lag[46]
  PPI
  Core PPI
  CPI
  Core CPI
  PCE
  Core PCE

Given that there are many possible measures of the price level, there are many possible measures of price inflation. Most frequently, the term "inflation" refers to a rise in a broad price index representing the overall price level for goods and services in the economy. The consumer price index (CPI), the personal consumption expenditures price index (PCEPI) and the GDP deflator are some examples of broad price indices. However, "inflation" may also be used to describe a rising price level within a narrower set of assets, goods or services within the economy, such as commodities (including food, fuel, metals), tangible assets (such as real estate), services (such as entertainment and health care), or labor. Although the values of capital assets are often casually said to "inflate," this should not be confused with inflation as a defined term; a more accurate description for an increase in the value of a capital asset is appreciation. The FBI (CCI), the producer price index, and employment cost index (ECI) are examples of narrow price indices used to measure price inflation in particular sectors of the economy. Core inflation is a measure of inflation for a subset of consumer prices that excludes food and energy prices, which rise and fall more than other prices in the short term. The Federal Reserve Board pays particular attention to the core inflation rate to get a better estimate of long-term future inflation trends overall.[47]

The inflation rate is most widely calculated by determining the movement or change in a price index, typically the consumer price index.[48]

The inflation rate is the percentage change of a price index over time. The Retail Prices Index is also a measure of inflation that is commonly used in the United Kingdom. It is broader than the CPI and contains a larger basket of goods and services. Inflation is politically driven, and policy can directly influence the trend of inflation.

The RPI is indicative of the experiences of a wide range of household types, particularly low-income households.[49]

To illustrate the method of calculation, in January 2007, the U.S. Consumer Price Index was 202.416, and in January 2008 it was 211.080. The formula for calculating the annual percentage rate inflation in the CPI over the course of the year is: (211.080202.416202.416)×100%=4.28%

The resulting inflation rate for the CPI in this one-year period is 4.28%, meaning the general level of prices for typical U.S. consumers rose by approximately four percent in 2007.[50]

Other widely used price indices for calculating price inflation include the following:

  • Producer price indices (PPIs) which measures average changes in prices received by domestic producers for their output. This differs from the CPI in that price subsidization, profits, and taxes may cause the amount received by the producer to differ from what the consumer paid. There is also typically a delay between an increase in the PPI and any eventual increase in the CPI. Producer price index measures the pressure being put on producers by the costs of their raw materials. This could be "passed on" to consumers, or it could be absorbed by profits, or offset by increasing productivity. In India and the United States, an earlier version of the PPI was called the Wholesale price index.
  • Commodity price indices, which measure the price of a selection of commodities. In the present commodity price indices are weighted by the relative importance of the components to the "all in" cost of an employee.
  • Core price indices: because food and oil prices can change quickly due to changes in supply and demand conditions in the food and oil markets, it can be difficult to detect the long run trend in price levels when those prices are included. Therefore, most statistical agencies also report a measure of 'core inflation', which removes the most volatile components (such as food and oil) from a broad price index like the CPI. Because core inflation is less affected by short run supply and demand conditions in specific markets, central banks rely on it to better measure the inflationary effect of current monetary policy.

Other common measures of inflation are:

  • GDP deflator is a measure of the price of all the goods and services included in gross domestic product (GDP). The US Commerce Department publishes a deflator series for US GDP, defined as its nominal GDP measure divided by its real GDP measure.

GDP Deflator=Nominal GDPReal GDP

  • Regional inflation The Bureau of Labor Statistics breaks down CPI-U calculations down to different regions of the US.
  • Historical inflation Before collecting consistent econometric data became standard for governments, and for the purpose of comparing absolute, rather than relative standards of living, various economists have calculated imputed inflation figures. Most inflation data before the early 20th century is imputed based on the known costs of goods, rather than compiled at the time. It is also used to adjust for the differences in real standard of living for the presence of technology.
  • Asset price inflation is an undue increase in the prices of real assets, such as real estate.

In some cases, the measures are meant to be more humorous or to reflect a single place. This includes:

Issues in measuring[edit | edit source]

Measuring inflation in an economy requires objective means of differentiating changes in nominal prices on a common set of goods and services, and distinguishing them from those price shifts resulting from changes in value such as volume, quality, or performance. For example, if the price of a can of corn changes from $0.90 to $1.00 over the course of a year, with no change in quality, then this price difference represents inflation. This single price change would not, however, represent general inflation in an overall economy. Overall inflation is measured as the price change of a large "basket" of representative goods and services. This is the purpose of a price index, which is the combined price of a "basket" of many goods and services. The combined price is the sum of the weighted prices of items in the "basket". A weighted price is calculated by multiplying the unit price of an item by the number of that item the average consumer purchases. Weighted pricing is necessary to measure the effect of individual unit price changes on the economy's overall inflation. The consumer price index, for example, uses data collected by surveying households to determine what proportion of the typical consumer's overall spending is spent on specific goods and services, and weights the average prices of those items accordingly. Those weighted average prices are combined to calculate the overall price. To better relate price changes over time, indexes typically choose a "base year" price and assign it a value of 100. Index prices in subsequent years are then expressed in relation to the base year price.[56] While comparing inflation measures for various periods one has to take into consideration the base effect as well.

Inflation measures are often modified over time, either for the relative weight of goods in the basket, or in the way in which goods and services from the present are compared with goods and services from the past. Basket weights are updated regularly, usually every year, to adapt to changes in consumer behavior. Sudden changes in consumer behavior can still introduce a weighting bias in inflation measurement. For example, during the COVID-19 pandemic it has been shown that the basket of goods and services was no longer representative of consumption during the crisis, as numerous goods and services could no longer be consumed due to government containment measures ("lock-downs").[57][58]

Over time, adjustments are also made to the type of goods and services selected to reflect changes in the sorts of goods and services purchased by 'typical consumers'. New products may be introduced, older products disappear, the quality of existing products may change, and consumer preferences can shift. Different segments of the population may naturally consume different "baskets" of goods and services and may even experience different inflation rates. It is argued that companies have put more innovation into bringing down prices for wealthy families than for poor families.[59]

Inflation numbers are often seasonally adjusted to differentiate expected cyclical cost shifts. For example, home heating costs are expected to rise in colder months, and seasonal adjustments are often used when measuring inflation to compensate for cyclical energy or fuel demand spikes. Inflation numbers may be averaged or otherwise subjected to statistical techniques to remove statistical noise and volatility of individual prices.[60][61]

When looking at inflation, economic institutions may focus only on certain kinds of prices, or special indices, such as the core inflation index which is used by central banks to formulate monetary policy.[62]

Most inflation indices are calculated from weighted averages of selected price changes. This necessarily introduces distortion, and can lead to legitimate disputes about what the true inflation rate is. This problem can be overcome by including all available price changes in the calculation, and then choosing the median value.[63] In some other cases, governments may intentionally report false inflation rates; for instance, during the presidency of Cristina Kirchner (2007–2015) the government of Argentina was criticised for manipulating economic data, such as inflation and GDP figures, for political gain and to reduce payments on its inflation-indexed debt.[64][65]

Official vs. true vs. perceived inflation[edit | edit source]

The true inflation is one percentage point lower than the official one, according to research. Therefore, the 2% inflation target is needed to prevent the true inflation being close to zero or even deflation. The reasons are the following:[66]

  • Substitution effect: People buy fewer products with the highest price rises and more of those whose prices have risen less. Therefore, the price of their non-fixed shopping basket rises less than that of a fixed shopping basket.
  • Unobserved quality improvements: Even though statisticians try to take quality improvements into account, they are not able to do it fully. This is why people rather buy current products at the higher prices than old products at their old prices.
  • New goods: The current shopping basket is much better, because it has goods that you previously could not even dream of.[67]

Nevertheless, people overestimate the inflation even vs. the measured inflation. This is because they focus more on commonly-bought items than on durable goods, and more on price increases than on price decreases.[68] On the other hand, different people have different shopping baskets and hence face different inflation rates.[68]

Consumer price index by country in % (2024, relative to 2010)[69]

Cumulative inflation due to the compound effect can impact the perception of inflation.[70]

Inflation expectations[edit | edit source]

Inflation expectations or expected inflation is the rate of inflation that is anticipated for some time in the foreseeable future. There are two major approaches to modeling the formation of inflation expectations. Adaptive expectations models them as a weighted average of what was expected one period earlier and the actual rate of inflation that most recently occurred. Rational expectations models them as unbiased, in the sense that the expected inflation rate is not systematically above or systematically below the inflation rate that actually occurs.

A long-standing survey of inflation expectations is the University of Michigan survey.[71]

Inflation expectations affect the economy in several ways. They are more or less built into nominal interest rates, so that a rise (or fall) in the expected inflation rate will typically result in a rise (or fall) in nominal interest rates, giving a smaller effect if any on real interest rates. In addition, higher expected inflation tends to be built into the rate of wage increases, giving a smaller effect if any on the changes in real wages. Moreover, the response of inflationary expectations to monetary policy can influence the division of the effects of policy between inflation and unemployment (see monetary policy credibility).

Causes[edit | edit source]

Template:Organize section

Historical approaches[edit | edit source]

Theories of the origin and causes of inflation have existed since at least the 16th century. Two competing theories, the quantity theory of money and the real bills doctrine, appeared in various guises during century-long debates on recommended central bank behaviour. In the 20th century, Keynesian, monetarist and new classical (also known as rational expectations) views on inflation dominated post-World War II macroeconomics discussions, which were often heated intellectual debates, until some kind of synthesis of the various theories was reached by the end of the century.

Before 1936[edit | edit source]

The price revolution from ca. 1550–1700 caused several thinkers to present what is now considered to be early formulations of the quantity theory of money (QTM). Other contemporary authors attributed rising price levels to the debasement of national coinages. Later research has shown that also growing output of Central European silver mines and an increase in the velocity of money because of innovations in the payment technology, in particular the increased use of bills of exchange, contributed to the price revolution.[72]

An alternative theory, the real bills doctrine (RBD), originated in the 17th and 18th century, receiving its first authoritative exposition in Adam Smith's The Wealth of Nations.[73] It asserts that banks should issue their money in exchange for short-term real bills of adequate value. As long as banks only issue a dollar in exchange for assets worth at least a dollar, the issuing bank's assets will naturally move in step with its issuance of money, and the money will hold its value. Should the bank fail to get or maintain assets of adequate value, then the bank's money will lose value, just as any financial security will lose value if its asset backing diminishes. The real bills doctrine (also known as the backing theory) thus asserts that inflation results when money outruns its issuer's assets. The quantity theory of money, in contrast, claims that inflation results when money outruns the economy's production of goods.

During the 19th century, three different schools debated these questions: The British Currency School upheld a quantity theory view, believing that the Bank of England's issues of bank notes should vary one-for-one with the bank's gold reserves. In contrast to this, the British Banking School followed the real bills doctrine, recommending that the bank's operations should be governed by the needs of trade: Banks should be able to issue currency against bills of trading, i.e. "real bills" that they buy from merchants. A third group, the Free Banking School, held that competitive private banks would not overissue, even though a monopolist central bank could be believed to do it.[74]

The debate between currency, or quantity theory, and banking schools during the 19th century prefigures current questions about the credibility of money in the present. In the 19th century, the banking schools had greater influence in policy in the United States and Great Britain, while the currency schools had more influence "on the continent", that is in non-British countries, particularly in the Latin Monetary Union and the Scandinavian Monetary Union.

During the Bullionist Controversy during the Napoleonic Wars, David Ricardo argued that the Bank of England had engaged in over-issue of bank notes, leading to commodity price increases. In the late 19th century, supporters of the quantity theory of money led by Irving Fisher debated with supporters of bimetallism. Later, Knut Wicksell sought to explain price movements as the result of real shocks rather than movements in money supply, resounding statements from the real bills doctrine.[72]

In 2019, monetary historians Thomas M. Humphrey and Richard Timberlake published "Gold, the Real Bills Doctrine, and the Fed: Sources of Monetary Disorder 1922–1938".[75]

Keynes and the early Keynesians[edit | edit source]

John Maynard Keynes in his 1936 main work The General Theory of Employment, Interest and Money emphasized that wages and prices were sticky in the short run, but gradually responded to aggregate demand shocks. These could arise from many different sources, e.g. autonomous movements in investment or fluctuations in private wealth or interest rates.[26] Economic policy could also affect demand, monetary policy by affecting interest rates and fiscal policy either directly through the level of government final consumption expenditure or indirectly by changing disposable income via tax changes.

The various sources of variations in aggregate demand will cause cycles in both output and price levels. Initially, a demand change will primarily affect output because of the price stickiness, but eventually prices and wages will adjust to reflect the change in demand. Consequently, movements in real output and prices will be positively, but not strongly, correlated.[26]

Keynes' propositions formed the basis of Keynesian economics which came to dominate macroeconomic research and economic policy in the first decades after World War II.[12]:526 Other Keynesian economists developed and reformed several of Keynes' ideas. Importantly, Alban William Phillips in 1958 published indirect evidence of a negative relation between inflation and unemployment, confirming the Keynesian emphasis on a positive correlation between increases in real output (normally accompanied by a fall in unemployment) and rising prices, i.e. inflation. Phillips' findings were confirmed by other empirical analyses and became known as a Phillips curve. It quickly became central to macroeconomic thinking, apparently offering a stable trade-off between price stability and employment. The curve was interpreted to imply that a country could achieve low unemployment if it were willing to tolerate a higher inflation rate or vice versa.[12]:173

The Phillips curve model described the U.S. experience well in the 1960s but failed to describe the stagflation experienced in the 1970s.

Monetarism[edit | edit source]

CPI 1914–2022
  Inflation
  M2 money supply increases Year/Year
Inflation and the growth of money supply (M2)

During the 1960s the Keynesian view of inflation and macroeconomic policy altogether were challenged by monetarist theories, led by Milton Friedman.[12]:528–529 Friedman famously stated that:

Inflation is always and everywhere a monetary phenomenon.[76]

He revived the quantity theory of money by Irving Fisher and others, making it into a central tenet of monetarist thinking, arguing that the most significant factor influencing inflation or deflation is how fast the money supply grows or shrinks.[77]

The quantity theory of money, simply stated, says that any change in the amount of money in a system will change the price level. This theory begins with the equation of exchange:

MV=PQ,

where

M is the nominal quantity of money;
V is the velocity of money in final expenditures;
P is the general price level;
Q is an index of the real value of final expenditures.

In this formula, the general price level is related to the level of real economic activity (Q), the quantity of money (M) and the velocity of money (V). The formula itself is simply an uncontroversial accounting identity because the velocity of money (V) is defined residually from the equation to be the ratio of final nominal expenditure (PQ) to the quantity of money (M).[11]:81–107

Monetarists assumed additionally that the velocity of money is unaffected by monetary policy (at least in the long run), that the real value of output is also exogenous in the long run, its long-run value being determined independently by the productive capacity of the economy, and that money supply is exogenous and can be controlled by the monetary authorities. Under these assumptions, the primary driver of the change in the general price level is changes in the quantity of money.[11]:81–107 Consequently, monetarists contended that monetary policy, not fiscal policy, was the most potent instrument to influence aggregate demand, real output and eventually inflation. This was contrary to Keynesian thinking which in principle recognized a role for monetary policy, but in practice believed that the effect from interest rate changes to the real economy was slight, making monetary policy an ineffective instrument, preferring fiscal policy.[12]:528 Conversely, monetarists considered fiscal policy, or government spending and taxation, as ineffective in controlling inflation.[77]

Friedman also took issue with the traditional Keynesian view concerning the Phillips curve. He, together with Edmund Phelps, contended that the trade-off between inflation and unemployment implied by the Phillips curve was only temporary, but not permanent. If politicians tried to exploit it, it would eventually disappear because higher inflation would over time be built into the economic expectations of households and firms.[12]:528–529 This line of thinking led to the concept of potential output (sometimes called the "natural gross domestic product"), a level of GDP where the economy is stable in the sense that inflation will neither decrease nor increase. This level may itself change over time when institutional or natural constraints change. It corresponds to the Non-Accelerating Inflation Rate of Unemployment, NAIRU, or the "natural" rate of unemployment (sometimes called the "structural" level of unemployment).[12] If GDP exceeds its potential (and unemployment consequently is below the NAIRU), the theory says that inflation will accelerate as suppliers increase their prices. If GDP falls below its potential level (and unemployment is above the NAIRU), inflation will decelerate as suppliers attempt to fill excess capacity, cutting prices and undermining inflation.[78]

Rational expectations theory[edit | edit source]

In the early 1970s, rational expectations theory led by economists like Robert Lucas, Thomas Sargent and Robert Barro transformed macroeconomic thinking radically. They held that economic actors look rationally into the future when trying to maximize their well-being, and do not respond solely to immediate opportunity costs and pressures.[12]:529–530 In this view, future expectations and strategies are important for inflation as well. One implication was that agents would anticipate the likely behaviour of central banks and base their own actions on these expectations. A central bank having a reputation of being "soft" on inflation will generate high inflation expectations, which again will be self-fulfilling when all agents build expectations of future high inflation into their nominal contracts like wage agreements. On the other hand, if the central bank has a reputation of being "tough" on inflation, then such a policy announcement will be believed and inflationary expectations will come down rapidly, thus allowing inflation itself to come down rapidly with minimal economic disruption. The implication is that credibility becomes very important for central banks in fighting inflation.[12]:467–469

New Keynesians[edit | edit source]

Events during the 1970s proved Milton Friedman and other critics of the traditional Phillips curve right: The relation between the inflation rate and the unemployment rate broke down. Eventually, a consensus was established that the break-down was due to agents changing their inflation expectations, confirming Friedman's theory. As a consequence, the notion of a natural rate of unemployment (alternatively called the structural rate of unemployment) was accepted by most economists, meaning that there is a specific level of unemployment that is compatible with stable inflation. Stabilization policy must therefore try to steer economic activity so that the actual unemployment rate converges towards that level.[12]:176–189 The trade-off between the unemployment rate and inflation implied by Phillips thus holds in the short term, but not in the long term.[79] Also the oil crises of the 1970s causing at the same time rising unemployment and rising inflation (i.e. stagflation) led to a broad recognition by economists that supply shocks could independently affect inflation.[26][12]:529

During the 1980s a group of researchers named new Keynesians emerged who accepted many originally non-Keynesian concepts like the importance of monetary policy, the existence of a natural level of unemployment and the incorporation of rational expectations formation as a reasonable benchmark. At the same time they believed, like Keynes did, that various market imperfections in different markets like labour markets and financial markets were also important to study to understand both inflation generation and business cycles.[12]:533–534 During the 1980s and 1990s, there were often heated intellectual debates between new Keynesians and new classicals, but by the 2000s, a synthesis gradually emerged. The result has been called the new Keynesian model,[12]:535 the "new neoclassical synthesis"[80][81] or simply the "new consensus" model.[80]

View post-2000 to present[edit | edit source]

A common view beginning around the year 2000 and holding through to the present time on inflation and its causes can be illustrated by a modern Phillips curve including a role for supply shocks and inflation expectations beside the original role of aggregate demand (determining employment and unemployment fluctuations) in influencing the inflation rate.[12] Consequently, demand shocks, supply shocks and inflation expectations are all potentially important determinants of inflation,[82] confirming the basis of the older triangle model by Robert J. Gordon:[83]

  • Demand shocks may both decrease and increase inflation. So-called demand-pull inflation may be caused by increases in aggregate demand due to increased private and government spending,[84][85] etc. Conversely, negative demand shocks may be caused by contractionary economic policy.
  • Supply shocks may also lead to both higher or lower inflation, depending on the character of the shock. Cost-push inflation is caused by a drop in aggregate supply (potential output). This may be due to natural disasters, war or increased prices of inputs. For example, a sudden decrease in the supply of oil, leading to increased oil prices, can cause cost-push inflation. Producers for whom oil is a part of their costs could then pass this on to consumers in the form of increased prices.[86]
  • Inflation expectations play a major role in forming actual inflation. High inflation can prompt employees to demand rapid wage increases to keep up with consumer prices. In this way, rising wages in turn can help fuel inflation as firms pass these higher labor costs on to their customers as higher prices, leading to a feedback loop. In the case of collective bargaining, wage growth may be set as a function of inflationary expectations, which will be higher when inflation is high. This can cause a wage-price spiral. In a sense, inflation begets further inflationary expectations, which beget further (built-in) inflation.[86]

The important role of rational expectations is recognized by the emphasis on credibility on the part of central banks and other policy-makers.[80] The monetarist assertion that monetary policy alone could successfully control inflation formed part of the new consensus which recognized that both monetary and fiscal policy are important tools for influencing aggregate demand.[80][12]:528 Indeed, monetary policy is under normal circumstances considered to be the preferable instrument to contain inflation.[82][12] At the same time, most central banks have abandoned trying to target money growth as originally advocated by the monetarists. Instead, most central banks in developed countries focus on adjusting interest rates to achieve an explicit inflation target.[4][12]:505–509 The reason for central bank reluctance in following money growth targets is that the money stock measures that central banks can control tightly, e.g. the monetary base, are not very closely linked to aggregate demand, whereas conversely money supply measures like M2, which are in some cases more closely correlated with aggregate demand, are difficult to control for the central bank. Also, in many countries the relationship between aggregate demand and all money stock measures have broken down in recent decades, weakening further the case for monetary policy rules focusing on the money supply.[4]:608

However, while more disputed in the 1970s, surveys of members of the American Economic Association (AEA) since the 1990s have shown that most professional American economists generally agree with the statement "Inflation is caused primarily by too much growth in the money supply", while the same surveys have shown a lack of consensus by AEA members since the 1990s that "In the short run, a reduction in unemployment causes the rate of inflation to increase" has developed despite more agreement with the statement in the 1970s.[92]

Housing shortages,[93][94][95][96] immigration[97] and climate change[98][99][100][101] have been cited as significant drivers of inflation in the 21st century.

2021–2023 inflation surge[edit | edit source]

Most countries experienced the 2021–2023 inflation surge, peaking in 2022 and declining in 2023. The causes are believed to be a mixture of demand and supply shocks, whereas inflation expectations generally remained anchored.[102] Possible causes on the demand side include expansionary fiscal and monetary policy after the COVID-19 pandemic, whereas supply shocks include the 2021–2023 global supply chain crisis caused by the COVID-19 lockdowns[102] and the global energy crisis that was exacerbated by the 2022 Russian invasion of Ukraine.

The term sellers' inflation was coined during this period to describe the effect of corporate profits as a possible cause of inflation: Price inelasticity can contribute to inflation when firms consolidate, tending to support monopoly or monopsony conditions anywhere along the supply chain for goods or services. When this occurs, firms can provide greater shareholder value by taking a larger proportion of profits than by investing in providing greater volumes of their outputs.[103][104] Shortly after initial energy price shocks caused by the Russian invasion of Ukraine had subsided, oil companies found that supply chain constrictions, already exacerbated by the ongoing global pandemic, supported price inelasticity, i.e., they began lowering prices to match the price of oil when it fell much more slowly than they had increased their prices when costs rose.[105]

The quantity theory of money has long been popular with libertarian-conservative critics of the Federal Reserve. During the COVID pandemic and its immediate aftermath, the M2 money supply increased at the fastest rate in decades, leading some to link the growth to the 2021-2023 inflation surge. Fed chairman Jerome Powell said in December 2021 that the once-strong link between the money supply and inflation "ended about 40 years ago," due to financial innovations and deregulation. Previous Fed chairs Ben Bernanke and Alan Greenspan, had previously concurred with this position. The broadest measure of money supply, M2, increased about 45% from 2010 through 2015, far faster than GDP growth, yet the inflation rate declined during that period — the opposite of what monetarism would have predicted. A lower velocity of money than was historically the case[106] was also cited for a diminished effect of growth in the money supply on inflation.[107][108]

Surveys of economists conducted by the University of Chicago Booth School of Business in November 2021 and January 2022 showed that more economists agreed than disagreed (with many expressing uncertainty) that while contributing to rising prices in the United States, the global supply chain crisis would not contribute to a higher long-term inflation rate above the Federal Reserve's inflation target and was not the main driver of the inflation surge, but that the combined effect of the stimulative fiscal and monetary policies being implemented in the United States posed a risk of prolonged higher inflation.[109][110]

Heterodox views[edit | edit source]

Additionally, there are theories about inflation accepted by economists outside of the mainstream. The Austrian School stresses that inflation is not uniform over all assets, goods, and services. Inflation depends on differences in markets and on where newly created money and credit enter the economy. Ludwig von Mises said that inflation should refer to an increase in the quantity of money, that is not offset by a corresponding increase in the need for money, and that price inflation will necessarily follow, always leaving a poorer nation.[111][112][113]

Government debt[edit | edit source]

Government debt obligates the government to increase taxes, reduce spending or the government may resort to inflationary finance of the deficit.[114][115] Another direction which translates government debt to inflation is the motivation of governments to erode nominal debts by increasing inflation.[114][115] As a result, elevated debt heightens the risk of inflationary pressures in both the short and long run by boosting aggregate demand, shaping inflation expectations, crowding out private investment, and raising concerns about fiscal dominance.[115] It was found that in the short run, a permanent 1 percent of GDP increase in the primary deficit leads, after five years, to inflationary pressures equivalent to a $300–$1,250 loss in household purchasing power per household (in 2024 dollars).[115]

Effects of inflation[edit | edit source]

General effect[edit | edit source]

Restaurant increasing prices by $1.00 due to inflation

Inflation is the decrease in the purchasing power of a currency. That is, when the general level of prices rise, each monetary unit can buy fewer goods and services in aggregate. The effect of inflation differs on different sectors of the economy, with some sectors being adversely affected while others benefitting. For example, with inflation, those segments in society which own physical assets, such as property, stock etc., benefit from the price/value of their holdings going up, when those who seek to acquire them will need to pay more for them. Their ability to do so will depend on the degree to which their income is fixed. For example, increases in payments to workers and pensioners often lag behind inflation, and for some people income is fixed. Also, individuals or institutions with cash assets will experience a decline in the purchasing power of the cash. Increases in the price level (inflation) erode the real value of money (the functional currency) and other items with an underlying monetary nature.

Debtors who have debts with a fixed nominal rate of interest will see a reduction in the "real" interest rate as the inflation rate rises. The real interest on a loan is the nominal rate minus the inflation rate. The formula R = N-I approximates the correct answer as long as both the nominal interest rate and the inflation rate are small. The correct equation is r = n/i where r, n and i are expressed as ratios (e.g. 1.2 for +20%, 0.8 for −20%). As an example, when the inflation rate is 3%, a loan with a nominal interest rate of 5% would have a real interest rate of approximately 2% (in fact, it's 1.94%). Any unexpected increase in the inflation rate would decrease the real interest rate. Banks and other lenders adjust for this inflation risk either by including an inflation risk premium to fixed interest rate loans or lending at an adjustable rate.

Negative[edit | edit source]

Inflation is illustrated by the contrast between what R$100 could buy in 2010 and in 2022, observed by Lula during a meeting with women in Brasilândia.

High or unpredictable inflation rates are regarded as harmful to an overall economy. They add inefficiencies in the market and make it difficult for companies to budget or plan long-term. Inflation can act as a drag on productivity as companies are forced to shift resources away from products and services to focus on profit and losses from currency inflation.[56] Uncertainty about the future purchasing power of money discourages investment and saving.[116] Inflation hurts asset prices such as stock performance in the short-run, as it erodes non-energy corporates' profit margins and leads to central banks' policy tightening measures.[117] Inflation can also impose hidden tax increases. For instance, inflated earnings push taxpayers into higher income tax rates unless the tax brackets are indexed to inflation.

With high inflation, purchasing power is redistributed from those on fixed nominal incomes, such as some pensioners whose pensions are not indexed to the price level, towards those with variable incomes whose earnings may better keep pace with the inflation.[56] This redistribution of purchasing power will also occur between international trading partners. Where fixed exchange rates are imposed, higher inflation in one economy than another will cause the first economy's exports to become more expensive and affect the balance of trade. There can also be negative effects to trade from an increased instability in currency exchange prices caused by unpredictable inflation.

Hoarding
People buy durable and/or non-perishable commodities and other goods as stores of wealth, to avoid the losses expected from the declining purchasing power of money, creating shortages of the hoarded goods.
Social unrest and revolts
Inflation can lead to massive demonstrations and revolutions. Thomas Sargent, showed how the huge public debt hoarded by Louis XVI stimulated the French revolution.[118] After the revolution, inflation replaced debt as a tool for financing the debt.[119][120] The post-revolution hyperinflation is considered as one of the reason for the rise of Napoleon.[121][122][123] Likewise, the German hyperinflation is considered to be one of the reason for the rise of the Nazi party.[124][125] Inflation and in particular food inflation is considered one of the main reasons that caused the 2010–2011 Tunisian revolution[126] and the 2011 Egyptian revolution,[127] according to many observers including Robert Zoellick,[128] president of the World Bank. Tunisian president Zine El Abidine Ben Ali was ousted, Egyptian President Hosni Mubarak was also ousted after only 18 days of demonstrations, and protests soon spread in many countries of North Africa and Middle East. The high inflation in Iran, especially of food is considered as one of the main reasons for the 2025-2026 mass protests in Iran.[129][130][131]
Hyperinflation
If inflation becomes too high, it can cause people to severely curtail their use of the currency, leading to an acceleration in the inflation rate. High and accelerating inflation grossly interferes with the normal workings of the economy, hurting its ability to supply goods. Hyperinflation can lead people to abandon the use of the country's currency in favour of external currencies (dollarization), as has been reported to have occurred in North Korea.[132]
Allocative efficiency
A change in the supply or demand for a good will normally cause its relative price to change, signaling the buyers and sellers that they should re-allocate resources in response to the new market conditions. But when prices are constantly changing due to inflation, price changes due to genuine relative price signals are difficult to distinguish from price changes due to general inflation, so agents are slow to respond to them. The result is a loss of allocative efficiency.
Shoe leather cost
High inflation increases the opportunity cost of holding cash balances and can induce people to hold a greater portion of their assets in interest paying accounts. However, since cash is still needed to carry out transactions this means that more "trips to the bank" are necessary to make withdrawals, proverbially wearing out the "shoe leather" with each trip.
Menu cost
With high inflation, firms must change their prices often to keep up with economy-wide changes. But often changing prices is itself a costly activity whether explicitly, as with the need to print new menus, or implicitly, as with the extra time and effort needed to change prices constantly.
Tax
Inflation serves as a hidden tax on currency holdings.[133][134]

Positive[edit | edit source]

Labour-market adjustments
Nominal wages are slow to adjust downward. This can lead to prolonged disequilibrium and high unemployment in the labor market. Since inflation allows real wages to fall even if nominal wages are kept constant, moderate inflation enables labor markets to reach equilibrium faster.[135]
Room to maneuver
The primary tools for controlling the money supply are the ability to set the discount rate, the rate at which banks can borrow from the central bank, and open market operations, which are the central bank's interventions into the bonds market with the aim of affecting the nominal interest rate. If an economy finds itself in a recession with already low, or even zero, nominal interest rates, then the bank cannot cut these rates further (since negative nominal interest rates are impossible) to stimulate the economy – this situation is known as a liquidity trap.
Mundell–Tobin effect
According to the Mundell–Tobin effect, an increase in inflation leads to an increase in capital investment, which leads to an increase in growth.[136] The Nobel laureate Robert Mundell noted that moderate inflation would induce savers to substitute lending for some money holding as a means to finance future spending. That substitution would cause market clearing real interest rates to fall.[137] The lower real rate of interest would induce more borrowing to finance investment. In a similar vein, Nobel laureate James Tobin noted that such inflation would cause businesses to substitute investment in physical capital (plant, equipment, and inventories) for money balances in their asset portfolios. That substitution would mean choosing the making of investments with lower rates of real return. (The rates of return are lower because the investments with higher rates of return were already being made before.)[138] The two related effects are known as the Mundell–Tobin effect. Unless the economy is already overinvesting according to models of economic growth theory, that extra investment resulting from the effect would be seen as positive.
Instability with deflation
Economist S.C. Tsiang noted that once substantial deflation is expected, two important effects will appear; both a result of money holding substituting for lending as a vehicle for saving.[139] The first was that continually falling prices and the resulting incentive to hoard money will cause instability resulting from the likely increasing fear, while money hoards grow in value, that the value of those hoards are at risk, as people realize that a movement to trade those money hoards for real goods and assets will quickly drive those prices up. Any movement to spend those hoards "once started would become a tremendous avalanche, which could rampage for a long time before it would spend itself."[140] Thus, a regime of long-term deflation is likely to be interrupted by periodic spikes of rapid inflation and consequent real economic disruptions. The second effect noted by Tsiang is that when savers have substituted money holding for lending on financial markets, the role of those markets in channeling savings into investment is undermined. With nominal interest rates driven to zero, or near zero, from the competition with a high return money asset, there would be no price mechanism in whatever is left of those markets. With financial markets effectively euthanized, the remaining goods and physical asset prices would move in perverse directions. For example, an increased desire to save could not push interest rates further down (and thereby stimulate investment) but would instead cause additional money hoarding, driving consumer prices further down and making investment in consumer goods production thereby less attractive. Moderate inflation, once its expectation is incorporated into nominal interest rates, would give those interest rates room to go both up and down in response to shifting investment opportunities, or savers' preferences, and thus allow financial markets to function in a more normal fashion.

Cost-of-living allowance[edit | edit source]

The real purchasing power of fixed payments is eroded by inflation unless they are inflation-adjusted to keep their real values constant. In many countries, employment contracts, pension benefits, and government entitlements (such as social security) are tied to a cost-of-living index, typically to the consumer price index.[141] A cost-of-living adjustment (COLA) adjusts salaries based on changes in a cost-of-living index.[142] It does not control inflation, but rather seeks to mitigate the consequences of inflation for those on fixed incomes. Salaries are typically adjusted annually in low inflation economies. During hyperinflation they are adjusted more often.[141] They may also be tied to a cost-of-living index that varies by geographic location if the employee moves.

Annual escalation clauses in employment contracts can specify retroactive or future percentage increases in worker pay which are not tied to any index. These negotiated increases in pay are colloquially referred to as cost-of-living adjustments ("COLAs") or cost-of-living increases because of their similarity to increases tied to externally determined indexes.

Control of inflation[edit | edit source]

Monetary policy is the policy enacted by the monetary authorities (most frequently the central bank of a nation) to accomplish their objectives.[143] Among these, keeping inflation at a low and stable level is often a prominent objective, either directly via inflation targeting or indirectly, e.g. via a fixed exchange rate against a low-inflation currency area.

Historical approaches to inflation control[edit | edit source]

Historically, central banks and governments have followed various policies to achieve low inflation, employing various nominal anchors. Before World War I, the gold standard was prevalent, but was eventually found to be detrimental to economic stability and employment, not least during the Great Depression in the 1930s.[144] For the first decades after World War II, the Bretton Woods system initiated a fixed exchange rate system for most developed countries, tying their currencies to the US dollar, which again was directly convertible to gold.[145] The system disintegrated in the 1970s, however, after which the major currencies started floating against each other.[146] During the 1970s many central banks turned to a money supply target recommended by Milton Friedman and other monetarists, aiming for a stable growth rate of money to control inflation. However, it was found to be impractical because of the unstable relationship between monetary aggregates and other macroeconomic variables, and was eventually abandoned by all major economies.[144] In 1990, New Zealand as the first country ever adopted an official inflation target as the basis of its monetary policy, continually adjusting interest rates to steer the country's inflation rate towards its official target. The strategy was generally considered to work well, and central banks in most developed countries have over the years adapted a similar strategy.[147] As of 2023, the central banks of all G7 member countries can be said to follow an inflation target, including the European Central Bank and the Federal Reserve, who have adopted the main elements of inflation targeting without officially calling themselves inflation targeters.[147] In emerging countries fixed exchange rate regimes are still the most common monetary policy.[148]

Fixed exchange rates[edit | edit source]

Under a fixed exchange rate currency regime, a country's currency is tied in value to another single currency or to a basket of other currencies. A fixed exchange rate is usually used to stabilize the value of a currency, vis-a-vis the currency it is pegged to. It can also be used as a means to control inflation if the currency area tied to itself maintains low and stable inflation. However, as the value of the reference currency rises and falls, so does the currency pegged to it. This essentially means that the inflation rate in the fixed exchange rate country is determined by the inflation rate of the country the currency is pegged to. In addition, a fixed exchange rate prevents a government from using domestic monetary policy to achieve macroeconomic stability.[149]

As of 2023, Denmark is the only OECD country which maintains a fixed exchange rate (against the euro), but it is frequently used as a monetary policy strategy in developing countries.[148]

Gold standard[edit | edit source]

Two 20 krona gold coins from the Scandinavian Monetary Union, a historical example of an international gold standard

The gold standard is a monetary system in which a region's common medium of exchange is paper notes (or other monetary token) that are normally freely convertible into pre-set, fixed quantities of gold. The standard specifies how the gold backing would be implemented, including the amount of specie per currency unit. The currency itself has no innate value but is accepted by traders because it can be redeemed for the equivalent value of the commodity (specie). A U.S. silver certificate, for example, could be redeemed for an actual piece of silver.

Under a gold standard, the long term rate of inflation (or deflation) would be determined by the growth rate of the supply of gold relative to total output.[150] Critics argue that this will cause arbitrary fluctuations in the inflation rate, and that monetary policy would essentially be determined by an intersection of however much new gold was produced by mining and changing demand for gold for practical uses.[151][152] The gold standard was historically found to make it more difficult to stabilize employment levels and avoid recessions and was eventually abandoned everywhere.[144][153]

Demurrage currency[edit | edit source]

Freiwirtschaft economists theorize that demurrage currency could eliminate both inflation and deflation. There tends to be some interest cost that is built into the goods and services that consumers tend to purchase,[154]: so if demurrage currency eliminates interest rates, then prices are less likely to increase. Demurrage would also naturally cause the money supply to decrease, thus causing deflation. If a central bank issues and monitors demurrage currency as Gesell originally proposed, then it could replace all the money that disappears due to demurrage by printing money at a similar rate.[155] The money printing could create just enough inflation to cancel out the natural deflation of demurrage, thus achieving an inflation target of 0%.[156]

Wage and price controls[edit | edit source]

Another method attempted in the past have been wage and price controls ("incomes policies"). Temporary price controls may be used as a complement to other policies to fight inflation; price controls may make disinflation faster, while reducing the need for unemployment to reduce inflation. If price controls are used during a recession, the kinds of distortions that price controls cause may be lessened. However, economists generally advise against the imposition of price controls.[157][158][159]

Wage and price controls, in combination with rationing, have been used successfully in wartime environments. However, their use in other contexts is far more mixed. Notable failures of their use include the 1972 imposition of wage and price controls by Richard Nixon. More successful examples include the Prices and Incomes Accord in Australia and the Wassenaar Agreement in the Netherlands.

In general, wage and price controls are regarded as a temporary and exceptional measures, only effective when coupled with policies designed to reduce the underlying causes of inflation during the wage and price control regime, for example, winning the war being fought.

Inflation targeting[edit | edit source]

From its first inception in New Zealand in 1990, direct inflation targeting as a monetary policy strategy has spread to become prevalent among developed countries. The basic idea is that the central bank perpetually adjusts the bank rate to influence the country's inflation rate towards its official target. Changes in interest rates affect aggregate demand, aggregate supply and inflation in various ways, also called the monetary transmission mechanism.[160] The relation between unemployment and inflation is known as the Phillips curve.

In most OECD countries, the inflation target is about 2%.[161] Citizens show generally a high aversion to inflation.[162] On average voters prefer an inflation rate around 0%.[163]

See also[edit | edit source]

References[edit | edit source]

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