Prices in government and employer-sponsored health insurance markets only partially reflect insurers' expected costs of coverage for different enrollees. This can create inefficient distortions when consumers self-select into plans. We develop a simple model to study this problem and estimate it...

Most health insurance uses cost-sharing to reduce excess utilization. Supplemental insurance can blunt the impact of this cost-sharing, increasing utilization and exerting a negative externality on the primary insurer. This paper estimates the effect of private Medigap supplemental insurance on...

Government programs are often offered on an optional basis to market participants. We explore the economics of such voluntary regulation in the context of a Medicare payment reform, in which one medical provider receives a single, predetermined payment for a sequence of related healthcare...

A central question in the debate over privatized Medicare is whether increased government payments to private Medicare Advantage (MA) plans generate lower premiums for consumers or higher profits for producers. Using difference-in-differences variation brought about by a sharp legislative...

Health insurance confers benefits to the previously uninsured, including improvements in health, reductions in out-of-pocket spending, and reduced medical debt. But because the nominally uninsured pay only a small share of their medical expenses, health insurance also provides substantial...

This paper examines the implicit health insurance households receive from the ability to declare bankruptcy. Exploiting cross-state and within-state variation in asset exemption law, I show that uninsured households with greater seizable assets make higher out-of-pocket medical payments,...

Standard policies to correct market power and selection can be misguided when these two forces co-exist. Using a calibrated model of employer-sponsored health insurance, we show that the risk adjustment commonly used by employers to offset adverse selection often reduces the amount of...