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...

We study how risk management through hedging impacts firms and competition among firms in the life insurance industry - an industry with over 7 Trillion in assets and over 1,000 private and public firms. We show that firms that are likely to face costly external finance increase hedging after...

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...

Since the inception of Medicare Part D in 2006, mergers and acquisitions (M&A) and regulatory changes have led to increased concentration and reduced plan variety in the standalone prescription drug plan (PDP) portion of the market. We examine how this industry consolidation affects Medicare...

While the traditional role of insurers is to provide protection against idiosyncratic risks of individuals, insurers themselves face substantial uncertainties due to aggregate shocks. To prevent insurers from passing through aggregate risks to consumers, governments have increasingly adopted...

Insurance markets often feature consumer sorting along both an extensive margin (whether to buy) and an intensive margin (which plan to buy). We present a new graphical theoretical framework that extends the workhorse model to incorporate both selection margins simultaneously. A key insight from...

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...

Should choice be offered in social insurance programs? The paper presents a conceptual framework that identifies the key forces determining the value of offering choice, reviews some existing evidence on these forces, and aims to guide further empirical research in different in- surance domains....

A positive correlation between insurance coverage and ex post risk can be an indicator for private information in insurance markets. However, this test fails if agents have heterogeneous risk attitudes. We propose a new test that conditions on unobserved types of individuals who differ in their...

We present a graphical framework for analyzing both theoretical and empirical work on selection in insurance markets. We begin by using this framework to review the "textbook" adverse selection environment and its implications for insurance allocation, social welfare, and public policy. We then...