J. M. Keynes

John Maynard Keynes was a British economist whose ideas fundamentally changed the theory and practice of macroeconomics and the economic policies of governments. He is best known for his work during the Great Depression, where he argued that total spending in an economy (aggregate demand) is the primary driver of economic growth and employment. His seminal book, 'The General Theory of Employment, Interest and Money,' published in 1936, challenged the classical economics of the time and introduced concepts such as the importance of government intervention in the economy to stimulate demand. Keynes' theories laid the groundwork for modern macroeconomic thought and continue to influence policymakers and economists today.