The Mortality and Medical Costs of Air Pollution: Evidence from Changes in Wind Direction
With Tatyana Deryugina, Garth Heutel, Nolan Miller, and Julian Reif
American Economic Review, December 2019
View abstract | NBER working paper #22796
Abstract: We estimate the causal effects of acute fine particulate matter exposure on mortality, health care use, and medical costs among the US elderly using Medicare data. We instrument for air pollution using changes in local wind direction and develop a new approach that uses machine learning to estimate the life-years lost due to pollution exposure. Finally, we characterize treatment effect heterogeneity using both life expectancy and generic machine learning inference. Both approaches find that mortality effects are concentrated in about 25 percent of the elderly population.
Media: Bloomberg
What Do Workplace Wellness Programs Do? Evidence from the Illinois Workplace Wellness Study
With Damon Jones and Julian Reif
The Quarterly Journal of Economics, November 2019
View abstract | NBER working paper #24229 | Study website
Abstract: Workplace wellness programs cover over 50 million US workers and are intended to reduce medical spending, increase productivity, and improve well-being. Yet, limited evidence exists to support these claims. We designed and implemented a comprehensive workplace wellness program for a large employer and randomly assigned program eligibility and financial incentives at the individual level for nearly 5,000 employees. We find strong patterns of selection: during the year prior to the intervention, program participants had lower medical expenditures and healthier behaviors than nonparticipants. The program persistently increased health screening rates, but we do not find significant causal effects of treatment on total medical expenditures, other health behaviors, employee productivity, or self-reported health status after more than two years. Our 95 percent confidence intervals rule out 84 percent of previous estimates on medical spending and absenteeism.
External summaries: The NBER Digest, J-PAL North America
Media: Bloomberg, Marketplace, The New York Times, The Washington Post, [More coverage]
The Influence of Pioneer Investigators on Technology Adoption: Evidence from New Cancer Drugs
With Leila Agha
The Review of Economics and Statistics, March 2018
View abstract | NBER working paper #20878 | NIH Public Access PMC5947964
Abstract: Local opinion leaders may play a key role in easing information frictions associated with technology adoption. This paper analyzes the influence of physician investigators who lead clinical trials for new cancer drugs. By comparing diffusion patterns across 21 new cancer drugs, we separate correlated regional demand for new technology from information spillovers. Patients in the lead investigator’s region are initially 36% more likely to receive the new drug, but utilization converges within four years. We also find that superstar physician authors, measured by trial role or citation history, have broader influence than less prominent authors.
The Evolution of Physician Practice Styles: Evidence from Cardiologist Migration
American Economic Journal: Economic Policy, February 2018
View abstract | NBER working paper #22478 | NIH Public Access PMC5876705
Abstract: Physician treatment choices for observably similar patients vary dramatically across regions. This paper exploits cardiologist migration to disentangle the role of physician-specific factors such as preferences and learned behavior versus environment-level factors such as hospital capacity and productivity spillovers on physician behavior. Physicians starting in the same region and subsequently moving to dissimilar regions practice similarly before the move. After the move, physician behavior in the first year changes by 0.6–0.8 percentage points for each percentage point change in practice environment, with no further changes over time. This suggests environment factors explain between 60–80 percent of regional disparities in physician behavior.

Working Papers

Does When You Die Depend on Where You Live? Evidence from Hurricane Katrina
With Tatyana Deryugina
Revise and resubmit, American Economic Review
View abstract | NBER working paper #24822
Abstract: We follow Medicare cohorts over time and space to estimate Hurricane Katrina's long-run mortality effects on elderly and disabled victims initially living in New Orleans. Inclusive of the initial shock, the hurricane improved survival eight years past the storm by 1.74 percentage points. Migration to lower-mortality regions explains most of this survival increase. Migrants to low- versus high-mortality regions look similar at baseline, but migrants' subsequent mortality is 0.83–0.90 percentage points lower for each percentage-point reduction in local mortality, quantifying causal effects of place on mortality among this population. By contrast, migrants' mortality is unrelated to local Medicare spending.
External summaries: The NBER Bulletin on Aging and Health
Adaptation and the Mortality Effects of Temperature across U.S. Climate Regions
With Garth Heutel and Nolan Miller
Revised and resubmitted, The Review of Economics and Statistics
View abstract | NBER working paper #23271
Abstract: We estimate how the mortality effects of temperature vary across U.S. climate regions to assess local and national damages from projected climate change. Using 22 years of Medicare data, we find that both cold and hot days increase mortality. However, hot days are less deadly in warm places while cold days are less deadly in cool places. Incorporating this heterogeneity into end-of-century climate change assessments reverses the conventional wisdom on climate damage incidence: cold places bear more, not less, of the mortality burden. Allowing places to adapt to their future climate substantially reduces the estimated mortality effects of climate change.
Air Pollution and the Labor Market: Evidence from Wildfire Smoke
With Mark Borgschulte and Eric Zou
View abstract
Abstract: We estimate labor market responses to transient air pollution events using a novel linkage of satellite images of wildfire smoke plumes, pollution monitor data, and labor market outcomes in the United States. Smoke exposure reduces earnings in both the year of exposure and the following year, lowers labor force participation, and increases Social Security claiming and payments. With an average of 17 days of annual smoke exposure per person, earnings losses sum to 1.21 percent of annual labor income. We estimate that the welfare cost of these lost earnings is substantially higher than the mortality cost of wildfire smoke.

Work in Progress

Why Does Disability Increase During Recessions? Evidence from Medicare
With Colleen Carey and Nolan Miller
Blowing Smoke: Health Impacts of Wildfire Plume Dynamics
With Nolan Miller and Eric Zou
Peer Effects in the Workplace: Evidence from the Illinois Workplace Wellness Study
With Damon Jones and Julian Reif

Other Writing