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Emergency Visits for Thunderstorm-Related Respiratory Illnesses Among Older Adults
with Eric Zou, Christopher Worsham, Nolan Miller, David Molitor, and Anupam Jena
JAMA Internal Medicine, August 2020, 180(9): 1248-1250
Media: CNN, WebMD,
Article | Manuscript


Thunderstorm-related atmospheric changes are expected to increase in severity with rising global temperatures. Although large-scale evidence is limited, vulnerable populations, such as older adults or those with common chronic respiratory diseases, like asthma or chronic obstructive pulmonary disease (COPD), are expected to be susceptible to negative health effects from these changes. The objective of this study was to determine whether increases in emergency department (ED) visits for acute respiratory illnesses occur among Medicare beneficiaries in the days surrounding thunderstorms across the continental US.

Effects of a Workplace Wellness Program on Employee Health, Health Beliefs, and Medical Use: A Randomized Clinical Trial
with David Chan, Damon Jones, Laura Payne, and David Molitor
JAMA Internal Medicine, May 2020, 180(7): 952-960
Media: Health Affairs, Inside Higher Ed, Kaiser Family Foundation,
Article | Manuscript


Many employers use workplace wellness programs to improve employee health and reduce medical costs, but randomized evaluations of their efficacy are rare. This randomized clinical trial of 4834 employees of the University of Illinois at Urbana-Champaign was conducted from August 9, 2016, to April 26, 2018. Members of the treatment group (n=3300) received incentives to participate in the workplace wellness program. Members of the control group (n=1534) did not participate in the wellness program. The 2-year workplace wellness program included financial incentives and paid time off for annual on-site biometric screenings, annual health risk assessments, and ongoing wellness activities (eg, physical activity, smoking cessation, and disease management). Measures taken at 12 and 24 months included clinician-collected biometrics (16 outcomes), administrative claims related to medical diagnoses (diabetes, hypertension, and hyperlipidemia) and medical use (office visits, inpatient visits, and emergency department visits), and self-reported health behaviors and health beliefs (14 outcomes). Among the 4834 participants, no significant effects of the program on biometrics, medical diagnoses, or medical use were seen after 12 or 24 months. A significantly higher proportion of employees in the treatment group than in the control group reported having a primary care physician after 24 months. The intervention significantly improved a set of employee health beliefs on average: participant beliefs about their chance of having a body mass index greater than 30, high cholesterol, high blood pressure, and impaired glucose level jointly decreased by 0.07 SDs; however, effects on individual belief measures were not significant.

The Long-Run Dynamics of Electricity Demand: Evidence from Municipal Aggregation
with Tatyana Deryugina and Alex MacKay
American Economic Journal: Applied Economics, January 2020, 12(1): 86-114
Media: Development Impact
Article | Manuscript | Data and code


We study the dynamics of residential electricity demand by exploiting a natural experiment that produced large and long-lasting price changes in over 250 Illinois communities. Using a flexible difference-in-differences matching approach that accounts for the effect of current, past, and future price changes on current demand, we estimate a one-year price elasticity of -0.16, a two-year elasticity of -0.22, and a long-run elasticity between -0.31 and -0.35. We also provide compelling evidence that consumers increased electricity usage ahead of these announced price changes. Our findings highlight the importance of accounting for consumption dynamics when evaluating energy policy.

The Mortality and Medical Costs of Air Pollution: Evidence from Changes in Wind Direction
with Tatyana Deryugina, Garth Heutel, Nolan Miller, and David Molitor
American Economic Review, December 2019, 109(12): 4178-4219
Winner: iHEA Arrow Award for Best Paper in Health Economics
Media: Gizmodo, Medium
Article | Manuscript | Errata | Slides | Data and code


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.

What Do Workplace Wellness Programs Do? Evidence from the Illinois Workplace Wellness Study
with Damon Jones and David Molitor
Quarterly Journal of Economics, November 2019, 134(4): 1747-1791
Winner: NIHCM Foundation Research Award
Media: NBER Digest, New York Times, Washington Post,
Article | Manuscript | Study website | Slides | Data and code


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.

A Model of Addiction and Social Interactions
Economic Inquiry, April 2019, 57(2): 759-773
Article | Manuscript | Data and code


Many consumer behaviors are both addictive and social. Understanding how these two phenomena interact informs basic models of human behavior, and matters for policymakers when the behavior is regulated. I develop a new model of demand that incorporates both addiction and social interactions and show that, under certain conditions, social interactions reinforce the effects of addiction. I also show how the dynamics introduced by addiction can solve the pernicious problem of identifying the causal effects of social interactions. I then use the model to illustrate a new and important identification problem for studies of social interactions: existing estimates cannot be used to draw welfare conclusions or even to deduce whether social interactions increase aggregate demand. Finally, I develop a method which allows researchers to distinguish between two common forms of social interactions and draw welfare conclusions.

Did Medicare Part D Reduce Mortality?
with Jason Huh
Journal of Health Economics, May 2017, 53: 17-37
Article | Manuscript | Data and code


We investigate the implementation of Medicare Part D and estimate that this prescription drug benefit program reduced elderly mortality by 2.2 percent annually. This was driven primarily by a reduction in cardiovascular mortality, the leading cause of death for the elderly. There was no effect on deaths due to cancer, a condition whose drug treatments are covered under Medicare Part B. We validate these results by demonstrating that the changes in drug utilization following the implementation of Medicare Part D match the mortality patterns we observe. We calculate that the value of the mortality reduction is equal to $5 billion per year.

The Insurance Value of Medical Innovation
with Darius Lakdawalla and Anup Malani
Journal of Public Economics, January 2017, 145: 94-102
Policy: ICER technical brief
Article | Manuscript | Data and code


Economists think of medical innovation as a valuable but risky good, producing health benefits but increasing financial risk for consumers and healthcare payers. This perspective overlooks how innovation can lower physical risks borne by healthy patients facing the prospect of future disease. We present an alternative framework that accounts for all these sources of value and links them to the value of healthcare insurance. We show that any innovation worth buying reduces overall risk and generates positive insurance value on its own. We conduct a stylized numerical exercise to assess the potential empirical significance of our insights. Our calculations suggest that conventional methods meaningfully understate the value of historical health gains and disproportionately undervalue treatments for the most severe illnesses, where physical risk to consumers is the costliest. These calculations also suggest that the value of physical insurance from new technologies may exceed the financial spending risk that they pose.

Interpreting Pre-trends as Anticipation: Impact on Estimated Treatment Effects from Tort Reform
with Anup Malani
Journal of Public Economics, April 2015, 124: 1-17
Article | Manuscript | Data and code


While conducting empirical work, researchers sometimes observe changes in outcomes before adoption of a new policy. The conventional diagnosis is that treatment is endogenous. This observation is also consistent, however, with anticipation effects that arise naturally out of many theoretical models. This paper illustrates that distinguishing endogeneity from anticipation matters greatly when estimating treatment effects. It provides a framework for comparing different methods for estimating anticipation effects and proposes a new set of instrumental variables to address the problem that subjects' expectations are unobservable. Finally, this paper examines a specific set of tort reforms that was not targeted at physicians but was likely anticipated by them. Interpreting pre-trends as evidence of anticipation increases the estimated effect of these reforms by a factor of two compared to a model that ignores anticipation.

Incentives for Reporting Disease Outbreaks
with Ramanan Laxminarayan and Anup Malani
PLOS One, March 2014, 9(3): e90290
Article | Manuscript | Data and code


Countries face conflicting incentives to report infectious disease outbreaks. Reports of outbreaks can prompt other countries to impose trade and travel restrictions, which has the potential to discourage reporting. However, reports can also bring medical assistance to contain the outbreak, including access to vaccines. We compiled data on reports of meningococcal meningitis from 54 African countries between 1966 and 2002, a period marked by two events: first, a large outbreak reported from many countries in 1987 associated with the Hajj that resulted in more stringent requirements for meningitis vaccination among pilgrims; and second, another large outbreak in Sub-Saharan Africa in 1996 that led to a new international mechanism to supply vaccines to countries reporting a meningitis outbreak. We find that the Hajj vaccination requirements started in 1988 were associated with reduced reporting, especially among countries with relatively fewer cases reported between 1966 and 1979. After the vaccine provision mechanism was in place in 1996, reporting among countries that had previously not reported meningitis outbreaks increased. These results indicate that countries may respond to changing incentives to report outbreaks when they can do so. In the long term, these incentives are likely to be more important than surveillance assistance in prompt reporting of outbreaks.

The Relation Between Variance and Information Rent in Auctions
with Brett Katzman and Jesse Schwartz
International Journal of Industrial Organization, March 2010, 28(2): 127-130
Article | Manuscript


This paper examines the conventional wisdom, expressed in McAfee and McMillan's (1987) widely cited survey paper on auctions, that links increased variance of bidder values to increased information rent. We find that although the conventional wisdom does indeed hold in their (1986) model of a linear contract auction, this relationship is an artifact of that particular model and cannot be generalized. Using Samuelson's (1987) model, which is similar but allows for unobservable costs, we show that increased variance does not always imply increased information rent. Finally, we give the appropriate measure of dispersion (different from variance) that provides the link between the bidder value distribution and information rent.

Working papers

Teenage Driving, Mortality, and Risky Behaviors
with Jason Huh
American Economic Review: Insights, accepted


We investigate the effect of teenage driving on mortality and risky behaviors in the United States using a regression discontinuity design. We estimate that total mortality rises by 5.84 deaths per 100,000 (15%) at the minimum legal driving age cutoff, driven by an increase in motor vehicle fatalities of 4.92 deaths per 100,000 (44%). We also find that poisoning deaths, which are caused primarily by drug overdoses, rise by 0.31 deaths per 100,000 (29%) at the cutoff and that this effect is concentrated among females. Our findings show that teenage driving contributes to sex differences in risky drug use behaviors.

Health Risk and the Value of Life
with Daniel Bauer and Darius Lakdawalla
Manuscript | Data and code


We develop a stochastic life-cycle framework for valuing health and longevity improvements and apply it to data on mortality, quality of life, and medical spending for adults with different comorbidities. People in the sickest health state are willing to pay 2.4 times more per quality-adjusted life-year (QALY) than healthy people. Even among the healthy, prevention of serious health risks is worth 16% more per QALY than prevention of mild risks. Our results help explain why people oppose the use of a single threshold value for rationing care and why people invest less in prevention than in treatment.

Book chapters

Geographic and Socioeconomic Heterogeneity in the Benefits of Reducing Air Pollution in the United States
with Tatyana Deryugina, Nolan Miller, and David Molitor
Environmental and Energy Policy and the Economy, 2021, 157-189. University of Chicago Press
Article | Manuscript


Policies aimed at reducing the harmful effects of air pollution exposure typically focus on areas with high levels of pollution. However, if a population’s vulnerability to air pollution is imperfectly correlated with current pollution levels, then this approach to air quality regulation may not efficiently target pollution reduction efforts. We examine the geographic and socioeconomic determinants of vulnerability to dying from acute exposure to fine particulate matter (PM 2.5) pollution. We find that there is substantial local and regional variability in the share of individuals who are vulnerable to pollution both at the county and ZIP code level. Vulnerability tends to be negatively related to health and socioeconomic status. Surprisingly, we find that vulnerability is also negatively related to an area’s average PM 2.5 pollution level, suggesting that basing air quality regulation only on current pollution levels may fail to effectively target regions with the most to gain by reducing exposure.

Health, Body Weight, and Obesity
with Darius Lakdawalla
Oxford Handbook of Economics and Human Biology, 2016, 152-178. Oxford University Press
Article | Manuscript


The rise in obesity has generated enormous concern among policy makers and the general public. Economists have focused on explaining the causes of this rise, along with the attendant implications for public policy. This chapter summarizes the economic literature on the theory of weight determination, including the optimal determination of food intake and exercise, and the influence of prices and peer effects. In addition, the chapter reviews the empirical literature that tests a range of explanations for the rise in obesity, such as declining food prices, increasing price of exercise, rising income, peer effects, and the decline in cigarette consumption.

The Complex Relationship Between Healthcare Reform and Innovation
with Darius Lakdawalla and Anup Malani
The Future of Healthcare Reform in the United States, 2015, 289-312. University of Chicago Press
Article | Manuscript


In this chapter we examine some of the interesting and important ways in which healthcare reform, particularly expansion of health insurance, affects innovation. We argue that the complexity and uncertainty of the relationship between insurance and innovation puts a premium on ability to experiment with alternative forms of healthcare reform.

Other publications

Economic Policy in President Biden’s First 100 Days
with Nolan Miller
University of Illinois Law Review Online, 30 April 2021
Article | Manuscript


In this article, we discuss six components of President Biden’s economic agenda: his response to the COVID-19 pandemic, domestic spending priorities, climate policy, tax policy, long-term fiscal policy, and immigration policy.

Air pollution policy should focus on the most vulnerable people, not just the most polluted places
with Tatyana Deryugina, Nolan Miller, and David Molitor
VoxEU, 13 January 2021
Article | Manuscript


Policies aimed at reducing the harmful effects of air pollution on human health typically focus on improving air quality in polluted areas. This column suggests a shift in focus from targeting the most polluted places to serving the most vulnerable people. Basing air quality regulations on pollution levels may be less valuable than reducing air pollution in regions with vulnerable populations. Programmes that reduce poverty or improve access to health care may also lessen the recipients’ susceptibility to acute pollution exposure.

Employee Wellness Programs: Reply
with Damon Jones and David Molitor
JAMA Internal Medicine, 21 December 2020
Article | Manuscript

The Illinois Workplace Wellness Study: Reply to Dr. Goetzel
with Damon Jones and David Molitor
American Journal of Health Promotion, 24 February 2020
Article | Manuscript

Workplace Wellness: New Study Finds No Changes in Health Care Costs
with Damon Jones and David Molitor
Scientific American, 19 March 2019
Article | Manuscript

Tools to Address Illinois Revenue: Increasing Sin Taxes
State Tax Notes, June 2014, 707-711
Article | Manuscript


In this report, I estimate the revenue that could be generated by increasing Illinois sin taxes on cigarettes, alcohol, and gambling. I discuss the efficiency and distributional effects of those taxes, as well as potential savings from a reduction in cigarette and alcohol consumption.

Works in progress

"Peer Effects in the Workplace: Evidence from the Illinois Workplace Wellness Study" (with Damon Jones and David Molitor)

"Pollution and Mortality in the United States: Evidence from 1972-1988" (with Tatyana Deryugina)

"Does Medicare Improve Quality of Life?"

"Evasion or Stockpiling? The Effect of Anticipated Future Tax Changes on Gasoline Sales" (with Don Fullerton)

External grants

An Impact Evaluation of i.c. stars Internship and Residency Program
Investigator, with Bill Skimmyhorn and Patrick Turner
J-PAL North America, 07/2020–06/2021, $50,000
University of Michigan Poverty Solutions, 07/2020–06/2021, $25,000
The Impact of Temperature and Pollution on Mortality, Morbidity, and Health Care Cost Among the Elderly
Investigator, with Tatyana Deryugina, Garth Heutel, Nolan Miller, and David Molitor
National Institute on Aging, R01 AG053350, 07/2016-06/2021

The Illinois Workplace Wellness Study
Principle Investigator, with Damon Jones, David Molitor, and Laura Payne
National Institute on Aging, R01 AG050701, 08/2015-04/2019, $1,230,680
J-PAL North America, 5710004125, 07/2016-06/2018, $321,990
National Science Foundation, 1730546, 08/2017-07/2020, $300,000
Robert Wood Johnson Foundation, 73730, 07/2016-01/2018, $200,000
Worksite Wellness: A Field Experiment on Participation Incentives and Selection into Wellness Programs
Early Career Research Award, with David Molitor
Upjohn Institute, 2017