The vast differences in economic development in the world are most likely caused by differences in institutions that create very different patterns of incentives and opportunities. The Chinese save and invest like mad, while in Congo there are no roads. This course asks: why? We take the view that institutions are collective choices and therefore the outcome of political processes. Thus the study of comparative economic development reduces to a series of questions about comparative politics; why do different countries make such different choices?; how do their political institutions influence those choices?; how is power distributed and how is it constrained or directed in the interests of society? The course both introduces the puzzles, some basic theoretical models which can help us think about these questions and the relevant social science evidence, though there are many things we don't really understand.