Greg Mankiw is a professor of economics at Harvard University and served as the chair of the Council on Economic Advisers under President George W. Bush. Today, he joins the show to discuss the history of macroeconomics and how macroeconomists function as both scientists, who formulate and test theories, and as engineers, who set out to solve real world problems. Greg also shares his thoughts on the debate between the New Keynesian School and New Classical School and how that debate has shaped how we think about economics.