Department of Economics
Princeton University
180 Julis Romo Rabinowitz Building
Princeton, NJ 08544

I am an Assistant Professor of Economics and Public Affairs at Princeton University.

Working papers

This paper estimates within-physician marginal returns to healthcare in a large but understudied segment of the healthcare sector -- the emergency department (ED). My empirical strategy exploits quasi-random assignment of physicians to coworker teams to generate instruments for case-level inputs based on workplace peer effects. Using time-stamped case-level data on millions of ED visits across New York State from 2005-2013 to infer time-varying coworker groups, I find that a physician's peers are influential in determining her pace of work. A variance decomposition that corrects for estimation noise and correlated shocks shows that peer effects have a variance one quarter to one third as large as physician effects within a hospital.

I use peer-induced variation in a physician's work pace to estimate the impacts of speeding a physician up on other inputs and on patient outcomes, namely 30-day mortality. I find robust evidence that physicians in fast-paced team environments ration care on other dimensions (tests and spending), causing increases in mortality among at-risk patients and cases with particularly vague symptoms. Among fast, low-spending physicians, marginal returns to time are high, whereas among slower physicians marginal returns are 0. At first glance, this is strong evidence of diminishing returns to treatment. However, the cross-physician relationship between intensity of care and patient outcomes is flat, suggesting that physicians operate on very different production functions, even within hospitals, and even within a single department of the hospital. Reallocation of time and testing away from slow physicians to fast physicians could produce efficiency gains. I discuss implications for increasingly popular physician-targeted incentives to cut back on wasteful care.


"The Health Effects of Cesarean Section: Evidence From the First Year of Life" (with David Card and Alessandra Fenizia) [draft in progress]

"Aging and Productivity: Evidence From Emergency Physicians" [draft in progress]

"Peer Effects in the Emergency Department" (with Juan Pablo Atal