Who was the British economist known for his influential theories on managing an economy during the 1930s?

John Maynard Keynes was a pivotal figure in economics, especially known for his revolutionary ideas that emerged during the Great Depression of the 1930s. He challenged traditional economic thought by emphasizing the importance of government intervention in stabilizing the economy. Keynes proposed that during times of economic downturns, such as severe recessions, government spending should increase to stimulate demand and pull an economy out of stagnation. This contrasted sharply with classical economics, which advocated for minimal government involvement.

Keynes' theories laid the groundwork for modern macroeconomic policy, advocating that active government fiscal policy could help manage economic cycles effectively. His ideas had a lasting impact, influencing policies worldwide and establishing the foundation for what is often referred to as Keynesian economics. The other economists mentioned, such as Adam Smith and David Ricardo, primarily contributed to classical economics, which focused more on laissez-faire principles and market self-regulation, while Milton Friedman, a significant figure in the mid-20th century, championed monetarism rather than the fiscal approaches that Keynes advocated.