Collusion through Common Leadership (with Alejandro Herrera-Caicedo and Jessica Jeffers) [download]. Accepted at Journal of Political Economy.
Coverage: NBER Digest
Antitrust Enforcement in Labor Markets [download]. Journal of Economic Perspectives, 2026, 40(1): 115-138.
Tiered Network Health Plans and Changes in Physician Practice Intensity (with Anna Sinaiko) [download]. Health Services Research, 2024, 59(1):e14163.
Employed in a SNAP? The Impact of Work Requirements on Program Participation and Labor Supply (with Colin Gray, Adam Leive, Kelsey Pukelis, and Mary Zaki) [download]. AEJ: Economic Policy, 2023, 15(1): 306-341. Winner of the 2026 AEJ Best Paper Award.
Coverage: NPR's The Indicator, NPR Here & Now, NPR Marketplace (1, 2), Time, Vox's The Weeds, The Messenger, Newsweek, Kellogg Insight
Policy impact: cited in Congressional testimony (1, 2, 3, 4, 5), CMS decision letters (1, 2), GAO Congressional report
Tiered Physician Network Plans and Patient Choices of Specialist Physicians (with Vilsa Curto, Alexa Magyari, Marema Gaye, and Anna Sinaiko) [download]. JAMA Network Open, 2023, 6(11):e2341836.
Employer Consolidation and Wages: Evidence from Hospitals (with Matt Schmitt) [download]. American Economic Review, 2021, 111(2): 397-427. Lead article.
Coverage: New York Times, Freakonomics, Modern Healthcare, Healthcare Dive, Kellogg Insight
Policy impact: FTC statements (1, 2), CEA post (explains Executive Order), Treasury report, cited in Congressional testimony (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14), White House report, 2024 HSR final rule
Health Care Demand Under Simple Prices: Evidence From Tiered Hospital Networks [download]. AEJ: Applied Economics, 2020, 12(4): 196-223.
Coverage: NPR's Arm and a Leg, Kellogg Insight
Policy impact: CMS rule, CBO models (1, 2), House report
Regulating Out-of-Network Hospital Payments: Disagreement Payoffs, Negotiated Prices, and Access (with Nicholas Tilipman) [download]
R&R at Journal of Political Economy
Recent policy proposals seek to regulate out-of-network hospital prices. We study how such regulation affects equilibrium prices, network formation, and hospital exit. We estimate a structural model of insurer-hospital bargaining that allows for out-of-network transactions between non-contracting parties. These transactions generate a notion of exit by rendering hospitals unprofitable under some regulations. Estimation relies on a novel measure of out-of-network prices. We find that reducing out-of-network prices would also lower negotiated prices, but potentially at the cost of narrower hospital networks. Aggressive regulation could induce substantial hospital exit, but only under the restrictive assumption that negotiators cannot anticipate the exits.
Extending Premerger Notification to Labor Markets (with Eric Posner) [download]
Invited at Review of Industrial Organization
US antitrust law requires mergers above a certain size to be reported to the federal antitrust agencies for review prior to consummation. For decades, this premerger notification process and subsequent merger review focused nearly exclusively on product markets. In the last few years, the agencies have also begun to challenge mergers on their effects on labor markets. But the agencies' ability to detect potential labor market harms is hampered by an absence of labor market information at the premerger notification stage. This article proposes specific types of information that the agencies could collect about labor markets in order to put labor market competition on an equal footing with product market competition in merger review. We make proposals for both the initial premerger notification required for all mergers above the size threshold (the HSR Form) and the additional information requested by the agencies when a preliminary analysis reveals potential concerns about competition (the Second Request). The majority of our proposals have direct analogs in product market information that has been sought for decades, raising the probability that courts will uphold them.
Peer Influence in College Applications (with Ana Gazmuri) [download]
This paper studies how exposure to peers affects college application behavior. In our setting, admission probabilities are observable and conditionally independent across programs. This allows us to recast the NP-hard problem of college application portfolio choice into a tractable form. Identification relies on students living in the same neighborhood but attending different high schools to mitigate concerns about common shocks. We find that exposure to peers who have applied to a program increases application rates. Counterfactual analyses suggest that the magnitude of the effect is large enough to close urban-rural gaps and gender gaps in applications to selective college programs.
Bargaining Under Price Transparency: Evidence from Hospital-Insurer Negotiations (with Maryam Saeedi, Robert Town, and Shruthi Venkatesh)
Labor Market Collusion and Careers (with Alejandro Herrera-Caicedo and Jessica Jeffers)
The Value of Alumni Networks: Evidence from Referrals to Medical School Classmates (with Alexa Magyari and Anna Sinaiko) [draft available upon request]
The Impact of Hospital Mergers and Acquisitions on Consumer Finances (with Alexander Adia, Ambar La Forgia, and Adam Leive)
Hospitals Are Paid Their Chargemaster Prices by Some Health Insurers (with Nicholas Tilipman)
Tiered Hospital Networks, Health Care Demand, and Prices