The economist John Maynard Keynes is best known for his theories on macroeconomics, which have had a lasting impact on economic policy. He is often referred to by his last name, Keynes, which is also the answer to the crossword puzzle clue. His most famous work, The General Theory of Employment, Interest and Money, was published in 1936 and revolutionized economic thought. Keynes' theories are still widely used today and have been adapted to fit modern economic conditions.