Three quarters of the world’s poor are farmers in developing countries. Their earnings from farming have been depressed by a pro-urban bias in own-country policies as well as by governments of richer countries favoring their farmers with import barriers and subsidies. Both sets of policies worsened from the 1960s to the mid-1980s, reducing national and global economic welfare and increasing inequality and poverty. The situation has improved over the past 20 years, but many trade-reducing distortions remain. Some developing countries have become agricultural protectionists. Many countries continue to try to insulate their domestic food markets from year-to-year fluctuations in international prices—thereby adding to those fluctuations and hence hurting other countries. This seminar examines the extent of these changes over the past five decades. It draws on a new methodology and empirical results from a recent research project spanning 74 countries that account for 92 percent of global agriculture and points to prospects for further policy reform and to how the WTO’s Doha Development Agenda could contribute.