The Impacts of Physician Payments on Patient Access, Use, and Health
(NBER Working Paper No. 26095) with Diane Alexander

Abstract: We examine how the amount a physician is paid influences who they are willing to see. Exploiting large, exogenous changes in Medicaid reimbursement rates, we find that increasing payments for new patient office visits reduces reports of providers turning away beneficiaries: closing the gap in payments between Medicaid and private insurers would reduce more than two-thirds of disparities in access among adults and would eliminate disparities among children. These improvements in access lead to more office visits, better self-reported health, and reduced school absenteeism. Our results demonstrate that financial incentives for physicians drive access to care and have important implications for patient health.

Physician Behavior in the Presence of a Secondary Market: The Case of Prescription Opioids

Abstract: This paper examines how patient and physician behavior across legal and illegal markets have contributed to the US opioid epidemic. To do so, I design and estimate a model of physician behavior in the presence of an endogenous secondary market with patient search. To access prescription opioids for medical purposes or misuse, patients search over physicians on the legal, primary market or turn to an illegal, secondary market. Physicians, who care about their revenue and their impact on population health, take into account the existence of this secondary market when prescribing. Estimates demonstrate that the presence of a secondary market induces physicians to be more careful in their prescribing—thereby bringing prescriptions closer to their optimal level—but results in significant harm on net due to the reallocation of prescriptions for abuse.


Check Up Before You Check Out: Retail Clinics and Emergency Room Use (online appendix)
with Diane Alexander and Janet Currie
Journal of Public Economics, 2019, 178

Abstract: Given concern about inefficient use of the emergency room (ER) increasing health care costs, we use all ER visits in New Jersey from 2006–2014 to examine the impacts of retail clinics on ER use in a difference-in-difference framework. We find that among people residing close to an open retail clinic, the rate of ER use falls by 3.3–13.4 percent for preventable conditions and 5.7– 12.0 percent for minor acute conditions, while a range of placebo conditions are not affected. Our estimates suggest annual cost savings of nearly $70 million from reduced ER use if retail clinics were readily available across New Jersey.

Food Deserts and the Causes of Nutritional Inequality (online appendix)
with Hunt Allcott, Rebecca Diamond, Jean-Pierre Dubé, Jessie Handbury, and Ilya Rahkovsky
Quarterly Journal of Economics, 2019, 134(4): 1793–1844

Abstract: We study the causes of “nutritional inequality”: why the wealthy eat more healthfully than the poor in the United States. Exploiting supermarket entry and household moves to healthier neighborhoods, we reject that neighborhood environments contribute meaningfully to nutritional inequality. We then estimate a structural model of grocery demand, using a new instrument exploiting the combination of grocery retail chains’ differing presence across geographic markets with their differing comparative advantages across product groups. Counterfactual simulations show that exposing low-income households to the same products and prices available to high-income households reduces nutritional inequality by only about ten percent, while the remaining 90 percent is driven by differences in demand. These findings counter the argument that policies to increase the supply of healthy groceries could play an important role in reducing nutritional inequality.

Just What the Nurse Practitioner Ordered: Independent Prescriptive Authority and Population Mental Health (online appendix)
with Diane Alexander
Journal of Health Economics, 2019, 66: 145–162

Abstract: We examine whether relaxing occupational licensing to allow nurse practitioners (NPs)—registered nurses with advanced degrees—to prescribe medication without physician oversight improves population mental health. Exploiting time-series variation in independent prescriptive authority for NPs from 1990 to 2014, we find that broadening prescriptive authority leads to improvements in self-reported mental health and decreases in mental health–related mortality. These improvements are concentrated in areas that are underserved by physicians and among populations that have difficulty accessing physician-provided care. Our results demonstrate that extending independent prescriptive authority to NPs can help mitigate physician shortages and extend care to disadvantaged populations

Addressing the Opioid Epidemic: Is There a Role for Physician Education? (online appendix)
with Janet Currie
American Journal of Health Economics, 2018, 4(3): 383–410 

Abstract: Using national data on opioid prescriptions written by physicians from 2006 to 2014, we uncover a striking relationship between opioid prescribing and medical school rank. Even within the same specialty and practice location, physicians who completed their initial training at top medical schools write significantly fewer opioid prescriptions annually than physicians from lower-ranked schools. Additional evidence suggests that some of this gradient represents a causal effect of education rather than patient selection across physicians or physician selection across medical schools. Altering physician education may therefore be a useful policy tool in fighting the current epidemic.


U.S. Employment and Opioids: Is There a Connection?
with Janet Currie and Jonas Jin
Health and Labor Markets (Research in Labor Economics, Volume 47), 2019, 253–280

Abstract: This paper uses quarterly county-level data from 2006–2014 to examine the direction of causality in the relationship between per capita opioid prescription rates and employment-to-population ratios. We first estimate models of the effect of per capita opioid prescription rates on employment-to-population ratios, instrumenting opioid prescriptions for younger ages using opioid prescriptions to the elderly. We find that the estimated effect of opioids on employment-to-population ratios is positive but small for women, while there is no relationship for men. We then estimate models of the effect of employment-to-population ratios on opioid prescription rates using a shift-share instrument, and find ambiguous results. Overall, our findings suggest that there is no simple causal relationship between economic conditions and the abuse of opioids. Therefore, while improving economic conditions in depressed areas is desirable for many reasons, it is unlikely on its own to curb the opioid epidemic.


The Opioid Crisis: Tragedy, Treatments, and Trade-offs
SIEPR Policy Brief, February 2019

Research Roundup: What Does the Evidence Say About How to Fight the Opioid Epidemic?
with Jennifer Doleac and Anita Mukherjee
Brookings Institute, December 2018

A Closer Look at How the Opioid Epidemic Affects Employment
with Janet Currie
Harvard Business Review, August 2018

Evaluating the Economic Response to Japan's Earthquake
with David Weinstein
RIETI Policy Discussion Paper Series, February 2012