A ubiquitous form of government intervention in insurance markets is to provide compulsory, but partial, public insurance coverage and to allow voluntary purchases of supplementary insurance on the private market. Yet we know little about the effects of such programs on total insurance coverage...

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...

Standard theory suggests that optimal consumer cost-sharing in health insurance increases with the price elasticity of demand, yet publicly-provided drug coverage typically involves uniform cost-sharing across drugs. We investigate how private drug plans set cost-sharing in the context of...

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...

In the last two decades, Medicare spending has doubled in real terms despite the fact that the health of Medicare beneficiaries improved over this period. The goals of this paper are to document how trends in spending by age have changed among elderly Medicare beneficiaries in the last decade...

Rewarding inventors with inefficient monopoly power has long been regarded as the price of encouraging innovation. Public prescription drug insurance escapes that trade-off and achieves an elusive goal: lowering static deadweight loss, while simultaneously encouraging dynamic investments in...

We study the demand response to non-linear price schedules using data on insurance contracts and prescription drug purchases in Medicare Part D. Consistent with a static response of drug use to price, we document bunching of annual drug spending as individuals enter the famous "donut hole,"...

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...

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...