Keynesian economics (pronounced /ˈkeɪnziən/, also called Keynesianism and Keynesian theory) is a macroeconomic theory based on the ideas of 20th century British economist John Maynard Keynes. Keynesian economics argues that private sector decisions sometimes lead to inefficient macroeconomic outcomes and therefore, advocates active policy responses by the public sector, including monetary policy actions by the central bank and fiscal policy actions by the government to stabilize output over the business cycle. The theories forming the basis of Keynesian economics were first presented in The General Theory of Employment, Interest and Money, published in 1936; the interpretations of Keynes are contentious, and several schools of thought claim his legacy.

Keynesian economics advocates a mixed economy—predominantly private sector, but with a large role of government and public sector—and served as the economic model during the latter part of the Great Depression, World War II, and the post-war economic expansion (1945–1973), though it lost some influence following the stagflation of the 1970s. The advent of the global financial crisis in 2007 has caused a resurgence in Keynesian thought. The former British Prime Minister Gordon Brown, President of the United States Barack Obama, and other world leaders have used Keynesian economics to justify government stimulus programs for their economies.

See also:

• Science: Social Sciences: Economics: People: Keynes, John Maynard (16)

• Global Keynesianism
  jobsletter.org.nz
  By James K. Galbraith. Some points on how Keynesians should react to the global economy.
• Why Aren't We All Keynesians Yet
  web.mit.edu
  Short piece by economist Paul Krugman.
• Vulgar Keynesians by Paul Krugman
  web.mit.edu
  John Maynard Keynes himself was a magnificently subtle and innovative thinker. Yet one of his unfortunate if unintentional legacies was a style of thought--call it vulgar Keynesianism--that confuses and befogs economic debate to this day.