Home

I am a postdoctoral associate at the Tobin Center for Economic Policy at Yale University. From Fall 2020 onwards, I will be an assistant professor at the Harris School of Public Policy at the University of Chicago. My fields of interest are industrial organization, health economics, and public economics. I previously received my Ph.D. from UC Berkeley in 2019.

Contact:
zarek.brot-goldberg{at}yale.edu


Working Papers:
"Intermediation and Vertical Integration in the Market for Surgeons" (with Mathijs de Vaan) [revised draft coming soon! email me for the old one.]
Health care markets are increasingly dominated by large, highly-integrated systems. Understanding the impact of this integration on market outcomes is central to designing good antitrust and regulatory policy. Integration presents a central efficiency trade-off: It may improve the productive efficiency of care through coordination between primary care providers (PCPs) and specialists, but it may also reduce allocative efficiency by enabling systems to steer PCPs’ referrals towards affiliated specialists. We study how these forces shape referrals to orthopedic joint surgeons in Massachusetts. We find evidence of both effects: Breaking health systems' vertical ties would reallocate nearly 40% of patients away from formerly-integrated orthopedists but, counterintuitively, would also increase expected costs by 5%. This aggregate effect masks substantive cross-system heterogeneity in both the size of the efficiency gain and the extent of the allocative distortion.


Publications:
Quarterly Journal of Economics, 2017, 132(3): 1261-1318
[Online Appendix]
Measuring consumer responsiveness to medical care prices is a central issue in health economics and a key ingredient in the optimal design and regulation of health insurance markets. We study consumer responsiveness to medical care prices, leveraging a natural experiment that occurred at a large self-insured firm which forced all of its employees to switch from an insurance plan that provided free health care to a non-linear, high deductible plan. The switch caused a spending reduction between 11.79%-13.80% of total firm-wide health spending. We decompose this spending reduction into the components of (i) consumer price shopping (ii) quantity reductions (iii) quantity substitutions, finding that spending reductions are entirely due to outright reductions in quantity. We find no evidence of consumers learning to price shop after two years in high-deductible coverage. Consumers reduce quantities across the spectrum of health care services, including potentially valuable care (e.g. preventive services) and potentially wasteful care (e.g. imaging services). We then leverage the unique data environment to study how consumers respond to the complex structure of the high-deductible contract. We find that consumers respond heavily to spot prices at the time of care, and reduce their spending by 42% when under the deductible, conditional on their true expected end-of-year shadow price and their prior year end-of-year marginal price. In the first-year post plan change, 90% of all spending reductions occur in months that consumers began under the deductible, with 49% of all reductions coming for the ex ante sickest half of consumers under the deductible, despite the fact that these consumers have quite low shadow prices. There is no evidence of learning to respond to the true shadow price in the second year post-switch.
Media Coverage: New York Times [Economic View]New York Times [The Upshot]Washington Post [Wonkblog]Washington Post [Health & Science]Vox [1]Vox [2]CBS MoneywatchMarketplaceThe Conversation
This paper won the 24th Annual NIHCM Foundation Research Award in 2018.

Work in progress:
"Who Makes an Active Choice? Testing Models of Default Effects in Medicare Part D" (with Timothy Layton, Boris Vabson, and Adelina Yanyue Wang)
We study decision-making among low-income beneficiaries of Medicare Part D, documenting a new stylized fact: Only 16% of beneficiaries make an active choice of insurance plan when they initially qualify, with the rest instead receiving the default, a randomly-assigned plan. We find that these default assignments are persistent, with only one-third of assigned beneficiaries having actively chosen to switch out of their plan after five years of enrollment. This dynamic persistence is driven by inattention rather than adaptation: 92% of assigned beneficiaries switch plans when their default quasi-randomly changes from remaining in their plan to being reassigned to a random plan. Despite their inattention, beneficiaries respond to poor plan assignment fit by reducing their drug consumption by 8-15%, and consequentially experience small increases in their use of hospital services. Those who face the greatest risk of these consequences are not more likely to make active decisions, both ex ante and ex post. Our results are inconsistent with the class of boundedly-rational models of choice commonly used in the literature, and raise concerns about the ability of market-based insurance provision to efficiently elicit beneficiary preferences.

"Making Health Care Organizations Accountable: Vertical Structure and Payment Reform" (with Mathijs de Vaan)

"Productivity Spillovers and the Underprovision of Hospital Performance Incentives"

"The Incidence of Paperwork in Medicine: Authorization Restrictions in Medicaid" (with Boris Vabson)