From 1991 to 2003, the fraction of Medicaid recipients enrolled in HMOs and other forms of Medicaid managed care (MMC) increased from 11 percent to 58 percent. This increase was largely driven by state and local mandates that required most Medicaid recipients to enroll in an MMC plan....

We examine whether and to what extent consolidation in the U.S. health insurance industry is leading to higher employer-sponsored insurance premiums. We make use of a proprietary, panel dataset of employer-sponsored healthplans enrolling over 10 million Americans annually between 1998 and 2006...

Governments contract with private firms to provide a wide range of services. While a large body of previous work has estimated the effects of that contracting, surprisingly little has investigated how those effects vary with the generosity of the contract. In this paper we examine this issue in...

Governments often contract with private firms to provide public services such as health care and education. To decrease firms' incentives to selectively enroll low-cost individuals, governments frequently "risk-adjust" payments to firms based on enrollees' characteristics. We model how risk...