The General Theory of Employment, Interest and Money
It is based on the theory of John Maynard Keynes presented in his work "The General Theory of Employment, Interest and Money". It is one of the primary simplified representations in the modern field of macroeconomics, and is used by a broad array of economists, from libertarian, monetarist supporters of laissez-faire, such as Milton Friedman, to post-Keynesian supporters of economic interventionism, such as Joan Robinson.