Under Revision
Access to a regional academic medical center or "star" hospital is highly valued by nearby residents. However, in many insurance markets, network inclusion of star hospitals can be rare or accompanied with very high cost sharing. This paper analyzes why this is the case. I gather data on inclusion of star hospitals in the nation's largest individual insurance market, Medicare Advantage. Star hospital coverage in Medicare Advantage is high--70% of plans cover their county's star hospital compared to 34% in ACA exchanges. I examine the degree to which Medicare Advantage's high coverage is the result of two unique institutional features: (1) the presence of a public option in hospital price negotiations, the Traditional Medicare program; and (2) the mitigation of adverse selection through its stable population and well-calibrated risk adjustment system. Through estimation of demand and cost parameters, I show that the elimination of either feature would dramatically reduce inclusion.
Association of ACA Medicaid Expansion with Medicaid Receipt and Health Care Use in Low-Income Older Adults with Chronic Conditions
with Melissa McInerney, Jan Mellor, and Lindsay Sabik
Completed Economics Articles
with Mike Geruso, Tim Layton, Mark Shepard
Revise & Resubmit, RESTAT
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 frame-work that extends a workhorse model to incorporate both selection margins simultaneously. A key insight from our framework is that policies aimed at addressing one margin of selection often involve an economically meaningful trade-of on the other margin in terms of prices, enrollment, and welfare. Using data from Massachusetts, we illustrate these trade-offs in an empirical sufficient statistics approach that is tightly linked to the graphical framework we develop.


Completed Policy Articles
with Sharon Touw, David U. Himmelstein, Steffie Woolhandler, and Leah Zallman
Health Affairs Article
During the COVID-19 pandemic in the US, essential workers have provided health care, food, and other necessities, often incurring considerable risk. At the pandemic’s start, the federal government was in the process of tightening the “public charge” rule by adding nutrition and health benefits to the cash benefits that, if drawn, could subject immigrants to sanctions (for example, green card denial). Census Bureau data indicate that immigrants accounted for 13.6 percent of the population but 17.8 percent of essential workers in 2019. About 20.0 million immigrants held essential jobs, and more than one-third of these immigrants resided in US states bordering Mexico. Nationwide, 12.3 million essential workers and 18.9 million of their household members were at risk because of the new sanctions. The rule change (which was subsequently revoked) likely caused 2.1 million essential workers and household members to forgo Medicaid and 1.3 million to forgo Supplemental Nutrition Assistance Program assistance on the eve of the pandemic, highlighting the potential of immigration policy changes to exacerbate health risks.
with Christopher Avery, Ariella Kahn-Lang Spitzer, Amitabh Chandra
JAMA Letter
The label of “essential worker” reflects society’s needs but does not mean that society has compensated those workers for additional risks incurred on the job during the current pandemic. When an essential worker contracts severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), they pose a risk to the other members of their household. These members may be elderly or lack health insurance, and the household may have limited resources to care for a sick family member. We assessed the proportion of essential workers in the US population and described the economic vulnerability of their households.