Despite it being a huge humanitarian problem, why is HIV/AIDS the wrong disease to attack in Africa even if the objective is lowering overall HIV prevalence? What do neuroscience and economics have in common? If monthly gym members pay higher fees than annual gym members for the option to cancel each month, why are they much more likely to stay enrolled beyond one year than users committing for a year? If the price for an average meal has stayed relatively stable, how can restaurants afford offering increasingly bigger food portions to their customers? Does poor health cause poverty or poverty cause poor health? This course illuminates the answers to many of these questions and examines health issues pertinent to developing countries from the standpoint of economics. Traditionally, economics has focused on understanding prices, competitive markets, and the interactions between markets. Important topics such as monopolies and antitrust, income inequality, economic growth, and the business cycle continue to be central areas of inquiry in economics. Recently, though, the subject matter of economics has broadened so that economists today-and especially economists at Harvard-address a remarkable variety of social science questions. In this course, we will examine interactions between disease, environment and rational individual behavior in the context of developing countries.