Douglas Irwin, professor of economics at Dartmouth College and author of Free Trade Under Fire (Princeton University Press, 2015), joins the show to discuss the economic arguments for free trade and the reasons for the heated politics surrounding trade. He describes the history of U.S. trade policy from the Embargo Act of 1808 to the Smoot-Hawley Tariff of 1930 to the North American Free Trade Agreement (NAFTA). Finally, he and David discuss the role of the inter-war gold standard during the Great Depression.