We study the Medicare Part D prescription drug insurance program as a bellwether for designs of private, non-mandatory health insurance markets, focusing on the ability of consumers to evaluate and optimize their choices of plans. Our analysis of administrative data on medical claims in Medicare...

First-year insurer participation in the Health Insurance Marketplaces (HIMs) established by the Affordable Care Act is limited in many areas of the country. There are 3.9 participants, on (population-weighted) average, in the 395 ratings areas spanning the 34 states with federally facilitated...

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....

This paper investigates the effects of market-wide changes in health insurance by examining the single largest change in health insurance coverage in American history: the introduction of Medicare in 1965. I estimate that the impact of Medicare on hospital spending is substantially larger than...

We study the impact of the introduction of one of the major pillars of the social insurance system in the United States: the introduction of Medicare in 1965. Our results suggest that, in its first 10 years, the establishment of universal health insurance for the elderly had no discernible...

Motivated by widely publicized concerns that there are "too many" plans, we structurally estimate (and validate) an equilibrium model of the Medicare Part D market to study the welfare impacts of two feasible, similar-sized approaches for reducing choice. One reduces the maximum number of firm...

There is considerable controversy about the causes of regional variations in health care expenditures. We use vignettes from patient and physician surveys linked to Medicare expenditures at the Hospital Referral Region to test whether patient demand-side factors or physician supply-side factors...

I use the Medicare Part D prescription drug insurance market to examine the dynamics of firm interaction with consumers on an insurance exchange. Enrollment data show that consumers face switching frictions leading to inertia in plan choice, and a regression discontinuity design indicates...

Most existing work on the price elasticity of demand for health insurance focuses on employees' decisions to enroll in employer-provided plans. Yet any attempt to achieve universal coverage must focus on the uninsured, the vast majority of whom are not offered employer-sponsored insurance. 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...