The disease burden in low-income countries is extremely high. Malaria, respira-
tory infections, diarrhea, AIDS, and other diseases are estimated to kill more than
15 million people each year, most of them children. Yet the great majority of these
diseases can be prevented or treated. This article reviews microeconomic studies
of health-seeking behavior in low-income countries. Factors examined include in-
formation, peers, liquidity constraints, and nonrational preferences, such as present
bias. I then discuss the implications for policy, including the scope for mandates,
subsidies, and incentives.