This paper summarizes the many aspects of public policy for health care. I first consider government policy affecting individual behaviors. Government intervention to change individual actions such as smoking and drinking is frequently justified on externality grounds. External costs of smoking...

This paper uses data on health insurance choices by employees of Harvard University to examine the effect of alternative pricing rules on market equilibrium. In the mid-1990s, Harvard moved from a system of subsidizing more expensive insurance to a system of contributing an equal amount to each...

Standard theories of insurance, dating from Rothschild and Stiglitz (1976), stress the role of adverse selection in explaining the decision to purchase insurance. In these models, higher risk people buy full or near-full insurance, while lower risk people buy less complete coverage, if they buy...

This article describes the anatomy of health insurance. It begins by considering the optimal design of health insurance policies. Such policies must make tradeoffs appropriately between risk sharing on the one hand and agency problems such as moral hazard (the incentive of people to seek more...

Individual choice over health insurance policies may result in risk-based sorting across plans. Such adverse selection induces three types of losses: efficiency losses from individuals being allocated to the wrong plans; risk sharing losses since premium variability is increased; and losses from...

This study assesses the factors influencing the movement of people across health plans. We distinguish three types of cost-related transitions: adverse selection, the movement of the less healthy to more generous plans; adverse retention, the tendency for people to stay where they are when they...