The Economic Journal: The Quarterly Journal of The Royal Economic Society. December 1954. [Keynes and Supply Functions: A Rejoinder].

During the Great Depression of the 1930s, Keynes spearheaded a revolution in economic thinking, challenging the ideas of neoclassical economics that held that free markets would, in the short to medium term, automatically provide full employment, as long as workers were flexible in their wage demands. He argued that aggregate demand (total spending in the economy) determined the overall level of economic activity, and that inadequate aggregate demand could lead to prolonged periods of high unemployment, and since wages and labor costs are rigid downwards the economy will not automatically rebound to full employment. Keynes advocated the use of fiscal and monetary policies to mitigate the adverse effects of economic recessions and depressions. He detailed these ideas in his magnum opus, The General Theory of Employment, Interest and Money, published in late 1936. By the late 1930s, leading Western economies had begun adopting Keynes's policy recommendations. Almost all capitalist governments had done so by the end of the two decades following Keynes's death in 1946.