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...

Why do indemnity insurance plans cost substantially more per capita—77% more in our study—than HMOs? We answer this question using data from a large organization’s insurance pool, covering 215,000 lives. We decompose cost differences for eight major medical conditions into...

Requiring agents with private information to select from a menu of incentive schedules can yield efficiency gains. It will do so if, and only if, agents will receive further private information after selecting the incentive schedule but before taking the action that determines where on the...

Differences in ethical behavior between members of the upper and lower classes have been at the center of civic debates in recent years. This paper presents a framework for understanding how class affects ethical standards and behaviors. The framework is applied using data from a large Dutch...

A principal provides budgets to agents (e.g., divisions of a firm or the principal's children) whose expenditures provide her benefits, either materially or because of altruism. Only agents know their potential to generate benefits. We prove that if the more "productive" agents are also more...

A broad array of law enforcement strategies, from income tax to bank regulation, involve self-reporting by regulated agents and auditing of some fraction of the reports by the regulating bureau. Standard models of self-reporting strategies assume that although bureaus only have estimates of the...

Financial, managerial, and medical decisions often involve alternatives whose possible outcomes have uncertain probabilities. In contrast to alternatives whose probabilities are known, these uncertain alternatives offer the benefits of learning. In repeat-choice situations, such learning brings...