The Demand for Insurance and Rationale for a Mandate: Evidence from Workers' Compensation Insurance.

Workers' compensation insurance, which provides no-fault coverage for work-related injuries, is mandatory in nearly all states. We use administrative data from a unique market without a coverage mandate to estimate the demand for workers' compensation insurance, leveraging regulatory premium updates for identification. We find that a 1 percent increase in premiums leads to approximately a 0.3 percent decline in coverage. Drawing upon these estimates and data on costs, we examine potential justifications for government intervention to increase coverage. This analysis suggests that several forms of market failure-such as adverse selection, market power, and externalities-may not justify a mandate in this setting.

Do Larger Health Insurance Subsidies Benefit Patients or Producers? Evidence from Medicare Advantage.

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 difference­in­differences variation brought about by a sharp legislative change, we find that MA insurers pass through 45 percent of increased payments in lower premiums and an additional 9 percent in more generous benefits. We show that advantageous selection into MA cannot explain this incomplete pass­through. Instead, our evidence suggests that market power is important, with premium pass­through rates of 13 percent in the least competitive markets and 74 percent in the most competitive.

Estimating the Value of Public Insurance Using Complementary Private Insurance.

The welfare associated with public insurance is often difficult to quantify because the demand for coverage is unobserved and thus cannot be used to analyze welfare. However, in many settings, individuals can purchase private insurance to supplement public coverage. This paper outlines an approach to use data and variation from private complementary insurance to quantify welfare associated with counterfactuals related to compulsory public insurance. We then apply this approach using administrative data on disability insurance. Our findings suggests that public disability insurance generates substantial surplus for the sample population, and there may be gains to increasing the generosity of coverage.

Externalities and Taxation of Supplemental Insurance: A Study of Medicare and Medigap.

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 public Medicare spending using Medigap premium discontinuities in local medical markets that span state boundaries. Using administrative data on the universe of Medicare beneficiaries, we estimate that Medigap increases an individual's Medicare spending by 22.2 percent. We calculate that a 15 percent tax on Medigap premiums generates savings of $12.9 billion annually with a standard error of $4.9 billion.

THE EFFECT OF INSURANCE COVERAGE ON PREVENTIVE CARE.

Despite the growth in health insurance products that differentially cover preventive care and nonpreventive care, little is known about how preventive care utilization responds to targeted changes in coverage. Using administrative data from a large company, this paper examines the implementation of an insurance benefit design which differentially increased the price of nonpreventive care while decreasing the price of prevention. Leveraging a difference-in-differences research strategy, we find that preventive care utilization did not increase and even declined due to the differential price change. This evidence indicates a meaningful negative cross-price effect, suggesting that nonpreventive care and preventive care are complements.