The General Theory of Employment, Interest, and Money by John Maynard Keynes — Summary, Key Ideas & Quotes

Keynes challenges the classical belief that markets naturally reach full employment through flexible wages and prices. He argues that economies can settle into prolonged periods of high unemployment, because demand doesn’t always match supply. This insight undermined the prevailing confidence that economies would self-correct without intervention, especially during deep downturns like the Great Depression.

A core innovation is Keynes’s focus on aggregate demand—the total spending by households, businesses, and government—as the primary driver of economic output and employment. When aggregate demand falls short, businesses cut production and lay off workers, creating a vicious cycle. This means that insufficient demand, not just supply-side factors, can cause persistent unemployment.