School of economic thought that maintains that the money supply is the chief determinant of economic activity. Milton Friedman and his followers promoted monetarism as an alternative to Keynesian economics (seeJohn Maynard Keynes); their economic theories became influential in the 1970s and early 1980s. Monetarism holds that a change in the money supply directly affects and determines production, employment, and price levels, though its influence is evident only over a long and often variable period of time. Fundamental to the monetarist approach is the rejection of fiscal policy in favour of monetary rule. Friedman and others asserted that fiscal measures such as tax-policy changes or increased government spending have little significant effect on the fluctuations of the business cycle. They argued that government intervention in the economy should be kept to a minimum and asserted that economic conditions would change before specific policy measures designed to address them could take effect. Steady, moderate growth of the money supply, in their view, offered the best hope of assuring a constant rate of economic growth with low inflation. U.S. economic performance in the 1980s cast doubts on monetarism, and the proliferation of new types of bank deposits made it difficult to calculate the money supply.