Keynesian economics

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Keynesian economics (/ˈkeɪnziən/ KAYN-zee-ən; sometimes Keynesianism, named after British economist John Maynard Keynes) are the various macroeconomic theories and models of how aggregate demand (total spending in the economy) strongly influences economic output and inflation.^[1] In the Keynesian view, aggregate demand does not necessarily equal the productive capacity of the economy. It is influenced by a host of factors that sometimes behave erratically and impact production, employment, and inflation.^[2]

Keynesian economists generally argue that aggregate demand is volatile and unstable and that, consequently, a market economy often experiences inefficient macroeconomic outcomes, including recessions when demand is too low and inflation when demand is too high. Further, they argue that these economic fluctuations can be mitigated by economic policy responses coordinated between a government and their central bank. In particular, fiscal policy actions taken by the government and monetary policy actions taken by the central bank, can help stabilize economic output, inflation, and unemployment over the business cycle.^[3] Keynesian economists generally advocate a regulated market economy – predominantly private sector, but with an active role for government intervention during recessions and depressions.^[4]

Keynesian economics developed during and after the Great Depression from the ideas presented by Keynes in his 1936 book, The General Theory of Employment, Interest and Money.^[5] Keynes' approach was a stark contrast to the aggregate supply-focused classical economics that preceded his book. Interpreting Keynes's work is a contentious topic, and several schools of economic thought claim his legacy.

Keynesian economics has developed new directions to study wider social and institutional patterns during the past several  decades. Post-Keynesian and New Keynesian economists have developed Keynesian thought by adding concepts about  income distribution and labor market frictions and institutional reform. Alejandro Antonio advocates for “equality of place”  instead of “equality of opportunity” by supporting structural economic changes and universal service access and worker protections.  Greenwald and Stiglitz represent New Keynesian economists who show how contemporary market failures regarding credit  rationing and wage rigidity can lead to unemployment persistence in modern economies. Scholars including K.H.  Lee explain how uncertainty remains important according to Keynes because expectations and conventions together with psychological behaviour known as  "animal spirits" affect investment and demand. Tregub's empirical research of French consumption patterns between  2001 and 2011 serves as contemporary evidence for demand-based economic interventions. The ongoing developments prove  that Keynesian economics functions as a dynamic and lasting framework to handle economic crises and create inclusive economic  policies.

Keynesian economics, as part of the neoclassical synthesis, served as the standard macroeconomic model in the developed nations during the later part of the Great Depression, World War II, and the post-war economic expansion (1945–1973). It was developed in part to attempt to explain the Great Depression and to help economists understand future crises. It lost some influence following the oil shock and resulting stagflation of the 1970s.^[6] Keynesian economics was later redeveloped as New Keynesian economics, becoming part of the contemporary new neoclassical synthesis, that forms current-day mainstream macroeconomics.^[7] The 2008 financial crisis sparked the 2008–2009 Keynesian resurgence by governments around the world.^[8]