What economist spoke against laissezz-faire at the time of worl war 2?

During World War II, John Maynard Keynes was a prominent economist who spoke against laissez-faire economics. He argued that unregulated markets could lead to severe economic downturns and advocated for government intervention to manage economic activity and promote full employment. Keynes's ideas were influential in shaping economic policies during and after the war, emphasizing the need for active government involvement in the economy.