"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...

Although economic theory suggests that the federal government can influence spending by states through subsidies to programs that states operate, no recent work has quantified the magnitude of this effect for Medicaid, the largest program of this type in the U.S. We find that Medicaid spending...

Despite a vast literature on the determinants of prescription opioid use, the role of health insurance plans has received little attention. We study how the form of Medicare beneficiaries' drug coverage affects the volume of opioids they consume. We find that enrollment in Medicare Advantage,...