In the United States, households obtain health insurance through distinct market segments. We explore the economics of this segmentation by comparing coverage provided through small employers versus the individual marketplace. Using data from Oregon, we find households with group coverage spend...

Some states that have not adopted the Affordable Care Act (ACA) Medicaid expansions have stated concerns that the expansions may impair access to care and utilization for those who are already insured. We investigate such negative spillovers using a large panel of Medicare beneficiaries. Across...

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...

We analyze the role of search frictions in the market for commercial health insurance. Frictions increase the cost of insurance by enabling insurers to set price above marginal cost, and by creating incentives for inefficiently high levels of marketing. Frictions also lead to price dispersion...

We show how standard consumer and producer theory can be used to estimate welfare in insurance markets with selection. The key observation is that the same price variation needed to identify the demand curve also identifies how costs vary as market participants endogenously respond to price....

Most existing studies of risk selection in the employer-sponsored health insurance market are case studies of a single employer or of an employer coalition in a single market. We examine risk selection in the employer-sponsored market by applying a switcher' methodology to a national, panel data...

A feature of many insurance markets is that they combine vertical differentiation (all consumers prefer high to low-coverage policies) and adverse selection (high cost customers prefer high-coverage plans). Building on Novshek and Sonnenschein (1978) and Azevedo and Gottlieb (2017), this paper...

Revealed-preference measures of willingness to pay (WTP) capture the value of insurance only against the risk that remains when choosing insurance. This paper provides a method to translate observed market WTP and cost curves into an ex-ante value of insurance that can analyze the impact of...

A major provision of the Affordable Care Act was the creation of Health Insurance Marketplaces, which began operating for the 2014 plan year. Although enrollment initially grew in these markets, enrollment has fallen recently amid insurer exits and rising premiums. To better understand these...

Risk adjustment of payments to health plans is fundamental to regulated competition among private insurers, which serves as the basis of national health policy in many countries. To date, estimation and evaluation of a risk adjustment model has been a two-step process. In a first step, the...