Working Papers

Water Works: Causes and Consequences of Safe Drinking Water in America
With David Keiser, Bhash Mazumder, and Joseph Shapiro
Revise and resubmit, The Quarterly Journal of Economics
Abstract | Manuscript | Citation Abstract: Since the 1974 Safe Drinking Water Act, the US has spent $2 trillion to provide safe drinking water, yet 10–20 percent of drinking water violates standards. We study trends, causes, and consequences of US drinking water pollution. The analysis uses 230 million readings on 1,800 pollutants over decades that we obtained from 48 states via dozens of Freedom of Information Act and associated requests. We link pollution geographically to administrative Medicare data on older Americans’ health outcomes. Three findings emerge. First, US drinking water pollution is declining rapidly. The share of readings exceeding current health standards, for example, fell by half from 2003–2019. Unregulated pollutants declined more slowly. Low-income areas have higher pollution; patterns for Black and Hispanic communities are more complex. Second, loans provided by the Safe Drinking Water Act to cities substantially reduce pollution. These loans could eliminate pollution above health standards for $36 annually per person. Third, these loans significantly reduce mortality rates of older Americans, at a cost of $124,000 per premature death avoided. Although fiscal federalism cautions against federal funding of local public goods with few inter-jurisdictional externalities like drinking water, we estimate enormous net benefits from Safe Drinking Water Act loans.

Keiser, David, Bhash Mazumder, David Molitor, and Joseph Shapiro. 2023. “Water Works: Causes and Consequences of Safe Drinking Water in America.” Mimeo.

Do Cities Mitigate or Exacerbate Environmental Damages to Health?
With Corey White
Forthcoming, Regional Science and Urban Economics
Eprints: NBER Working Paper | IZA Discussion Paper
Abstract | Manuscript | Citation Abstract: Do environmental conditions pose greater health risks to individuals living in urban or rural areas? The answer is theoretically ambiguous: while urban areas have traditionally been associated with heightened exposure to environmental pollutants, the economies of scale and density inherent to urban environments offer unique opportunities for mitigating or adapting to these harmful exposures. To make progress on this question, we focus on the United States and consider how exposures—to air pollution, drinking water pollution, and extreme temperatures—and the response to those exposures differ across urban and rural settings. While prior studies have addressed some aspects of these issues, substantial gaps in knowledge remain, in large part due to historical deficiencies in monitoring and reporting, especially in rural areas. As a step toward closing these gaps, we present new evidence on urban-rural differences in air quality and population sensitivity to air pollution, leveraging recent advances in remote sensing measurement and machine learning. We find that the urban-rural gap in fine particulate matter (PM2.5) has converged over the last two decades and the remaining gap is small relative to the overall declines. Furthermore, we find that residents of urban counties are, on average, less vulnerable to the mortality effects of PM2.5 exposure. We also discuss promising areas for future research.

Molitor, David, and Corey White. 2023. “Do Cities Mitigate or Exacerbate Environmental Damages to Health?” NBER Working Paper 31990.

Do Earmarks Target Low-Income and Minority Communities? Evidence from US Drinking Water
With David Keiser, Bhash Mazumder, Joseph Shapiro, and Brant Walker
Selected for AEA Papers and Proceedings
Abstract | Manuscript | Citation Abstract: The quality and inequality of US drinking water investments have gained attention after recent environmental disasters in Flint, Michigan, and elsewhere. We compare the formula-based targeting of subsidized loans provided under the Safe Drinking Water Act against the targeting of congressional drinking water earmarks (“pork barrel” spending). Earmarks face concerns that they may privilege wealthier and more politically connected communities. We find that earmarks target Black, Hispanic, and low-income communities, partly due to targeting water systems serving large populations. Earmark and loan targeting differ significantly along all demographics we analyze. Compared to Safe Drinking Water Act loans, earmarks disproportionately target Hispanic though not Black or low-income communities.

Keiser, David, Bhash Mazumder, David Molitor, Joseph Shapiro, and Brant Walker. 2023. “Do Earmarks Target Low-Income and Minority Communities? Evidence from US Drinking Water.” Mimeo.

Why Does Disability Insurance Enrollment Increase During Recessions? Evidence from Medicare
With Colleen Carey and Nolan Miller
Media: Illinois News Bureau, The NBER Bulletin on Retirement and Disability
Eprints: NBER Working Paper | NBER RDRC Center Paper
Abstract | Manuscript | Citation Abstract: Social Security Disability Insurance (DI) awards rise in recessions, especially for older adults. Using Medicare data, we investigate how health and entry costs shape this pattern. We find that higher unemployment at application corresponds to increased DI entry, lower medical spending, and lower mortality among new entrants. We use age-based discontinuities in disability eligibility criteria as an instrument for DI entry to develop a model of the health of DI entrants at varying levels of unemployment. We find no shift in the health of marginal entrants as unemployment increases, indicating that health changes play little role in cyclical DI entry.

Carey, Colleen, Nolan Miller, and David Molitor. 2022. “Why Does Disability Insurance Enrollment Increase During Recessions? Evidence from Medicare.” NBER Working Paper 29988.

Air Pollution and the Labor Market: Evidence from Wildfire Smoke
With Mark Borgschulte and Eric Zou
Accepted, The Review of Economics and Statistics
Media: AP, CA Legislative Analyst, CBC, CBS, IL News Bureau, Insurance Journal, IZA, The New York Times, Quartz, SF Fed
Eprints: NBER Working Paper | IZA Discussion Paper
Abstract | Manuscript | Citation | Data and Code Abstract: We study how air pollution impacts the U.S. labor market by analyzing the effects of drifting wildfire smoke. We link satellite-based smoke plume data with labor market outcomes to estimate that an additional day of smoke exposure reduces quarterly earnings by about 0.1 percent. Extensive margin responses, including employment reductions and labor force exits, explain 13 percent of the overall earnings losses. The implied welfare costs from lost earnings due to air pollution exposure is on par with standard valuations of the mortality burden. The findings highlight the importance of labor market channels in air pollution policy responses.

Borgschulte, Mark, David Molitor, and Eric Zou. 2022. “Air Pollution and the Labor Market: Evidence from Wildfire Smoke.” NBER Working Paper 29952.

Publications

Air Pollution and Suicide in Rural and Urban America: Evidence from Wildfire Smoke
With Jamie Mullins and Corey White
Proceedings of the National Academy of Sciences, September 2023
Eprints: NIH Public Access
Media: Climate Central, CTV News, Daily Beast, Illinois News Bureau, NPR, SciAm, US News, Verite, WBBM Newsradio, WCIA
Abstract | Manuscript | Article | Citation | Appendix | Data and Code Abstract: Air pollution poses well-established risks to physical health, but little is known about its effects on mental health. We study the relationship between wildfire smoke exposure and suicide risk in the United States in 2007 to 2019 using data on all deaths by suicide and satellite-based measures of wildfire smoke and ambient fine particulate matter (PM2.5) concentrations. We identify the causal effects of wildfire smoke pollution on suicide by relating year-over-year fluctuations in county-level monthly smoke exposure to fluctuations in suicide rates and compare the effects across local areas and demographic groups that differ considerably in their baseline suicide risk. In rural counties, an additional day of smoke increases monthly mean PM2.5 by 0.41 μg/m³ and suicide deaths by 0.11 per million residents, such that a 1-μg/m³ (13\%) increase in monthly wildfire-derived fine particulate matter leads to 0.27 additional suicide deaths per million residents (a 2.0\% increase). These effects are concentrated among demographic groups with both high baseline suicide risk and high exposure to outdoor air: men, working-age adults, non-Hispanic Whites, and adults with no college education. By contrast, we find no evidence that smoke pollution increases suicide risk among any urban demographic group. This study provides large-scale evidence that air pollution elevates the risk of suicide, disproportionately so among rural populations.

Molitor, David, Jamie T. Mullins, and Corey White. 2023. “Air Pollution and Suicide in Rural and Urban America: Evidence from Wildfire Smoke.” Proceedings of the National Academy of Sciences, 120(38): e2221621120. https://doi.org/10.1073/pnas.2221621120.

The Causal Effects of Place on Health and Longevity
With Tatyana Deryugina
Journal of Economic Perspectives, November 2021
Eprints: NBER Working Paper | NIH Public Access | IZA Discussion Paper | CESifo Working Paper
Abstract | Manuscript | Article | Citation | Appendix | Data and Code Abstract: Life expectancy varies substantially across local regions within a country, raising conjectures that place of residence affects health. However, population sorting and other confounders make it difficult to disentangle the effects of place on health from other geographic differences in life expectancy. Recent studies have overcome such challenges to demonstrate that place of residence substantially influences health and mortality. Whether policies that encourage people to move to places that are better for their health or that improve areas that are detrimental to health are desirable depends on the mechanisms behind place effects, yet these mechanisms remain poorly understood.

Deryugina, Tatyana, and David Molitor. 2021. “The Causal Effects of Place on Health and Longevity.” Journal of Economic Perspectives, 35(4): 147–70.

Adaptation and the Mortality Effects of Temperature across U.S. Climate Regions
With Garth Heutel and Nolan Miller
The Review of Economics and Statistics, October 2021
Media: The Journalist's Resource
Eprints: NBER Working Paper
Abstract | Manuscript | Article | Citation | Appendix | Data and Code 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.

Heutel, Garth, Nolan H. Miller, and David Molitor. 2021. “Adaptation and the Mortality Effects of Temperature Across U.S. Climate Regions.” The Review of Economics and Statistics, 103(4): 740–753.

Geographic and Socioeconomic Heterogeneity in the Benefits of Reducing Air Pollution in the United States
With Tatyana Deryugina, Nolan Miller, and Julian Reif
Environmental and Energy Policy and the Economy, Volume 2, 2021
Eprints: NBER Working Paper
Abstract | Manuscript | Article | Citation Abstract: 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 (PM2.5) 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 PM2.5 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.

Deryugina, Tatyana, Nolan H. Miller, David Molitor, and Julian Reif. 2021. “Geographic and Socioeconomic Heterogeneity in the Benefits of Reducing Air Pollution in the United States.” Environmental and Energy Policy and the Economy, 2021, 2(1): 157–189.

Does When You Die Depend on Where You Live? Evidence from Hurricane Katrina
With Tatyana Deryugina
American Economic Review, November 2020
Media: The NBER Bulletin on Aging and Health, econimate (animation)
Eprints: NBER Working Paper | NIH Public Access
Abstract | Manuscript | Article | Citation | Appendix | Data and Code Abstract: We follow Medicare cohorts to estimate Hurricane Katrina’s long-run mortality effects on victims initially living in New Orleans. Including the initial shock, the hurricane improved eight-year survival by 2.07 percentage points. Migration to lower-mortality regions explains most of this survival increase. Those migrating to low- versus high-mortality regions look similar at baseline, but their subsequent mortality is 0.83–1.01 percentage points lower per percentage-point reduction in local mortality, quantifying causal effects of place on mortality among this population. Migrants’ mortality is also lower in destinations with healthier behaviors and higher incomes but is unrelated to local medical spending and quality.

Deryugina, Tatyana, and David Molitor. 2020. “Does When You Die Depend on Where You Live? Evidence from Hurricane Katrina.” American Economic Review, 110(11): 3602–33.

Emergency Visits for Thunderstorm-Related Respiratory Illnesses Among Older Adults
With Eric Zou, Christopher Worsham, Nolan H. Miller, Julian Reif, and Anupam B. Jena
JAMA Internal Medicine, August 2020
Media: CNN, Fox News, Gizmodo, The Wall Street Journal, WebMD, [More coverage]
Eprints: NIH Public Access
Abstract | Article | Citation Abstract: 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.

Zou E, Worsham C, Miller NH, Molitor D, Reif J, Jena AB. “Emergency Visits for Thunderstorm-Related Respiratory Illnesses Among Older Adults.” JAMA Intern Med. 2020;180(9):1248-1250. doi:10.1001/jamainternmed.2020.1672.

Effects of a Workplace Wellness Program on Employee Health, Health Beliefs, and Medical Use: A Randomized Clinical Trial
With Julian Reif, David Chan, Damon Jones, and Laura Payne
JAMA Internal Medicine, May 2020
Media: Health Affairs, Illinois News Bureau, Inside Higher Ed, Kaiser Family Foundation, The Washington Post, [More coverage]
Eprints: NIH Public Access
Abstract | Manuscript | Article | Citation | Appendix | Data and Code | Study Website

Importance Many employers use workplace wellness programs to improve employee health and reduce medical costs, but randomized evaluations of their efficacy are rare.

Objective To evaluate the effect of a comprehensive workplace wellness program on employee health, health beliefs, and medical use after 12 and 24 months.

Design, Setting, and Participants 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. Statistical analysis was performed on April 9, 2020.

Interventions 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).

Main Outcomes and Measures 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).

Results Among the 4834 participants (2770 women; mean [SD] age, 43.9 [11.3] years), 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 (1106 of 1200 [92.2%] vs 477 of 554 [86.1%]; adjusted P = .002). 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 (95%CI, −0.12 to −0.01 SDs; P = .02); however, effects on individual belief measures were not significant.

Conclusions and Relevance This randomized clinical trial showed that a comprehensive workplace wellness program had no significant effects on measured physical health outcomes, rates of medical diagnoses, or the use of health care services after 24 months, but it increased the proportion of employees reporting that they have a primary care physician and improved employee beliefs about their own health.

Reif J, Chan D, Jones D, Payne L, Molitor D. “Effects of a Workplace Wellness Program on Employee Health, Health Beliefs, and Medical Use: A Randomized Clinical Trial.” JAMA Intern Med. 2020;180(7):952–960. doi:10.1001/jamainternmed.2020.1321.

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
Media: Bloomberg, Gizmodo, Illinois News Bureau, Medium
Eprints: NBER Working Paper | NIH Public Access
Winner: iHEA Arrow Award for Best Paper in Health Economics
Abstract | Manuscript | Article | Citation | Appendix | Data and Code 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.

Deryugina, Tatyana, Garth Heutel, Nolan H. Miller, David Molitor, and Julian Reif. 2019. “The Mortality and Medical Costs of Air Pollution: Evidence from Changes in Wind Direction.” American Economic Review, 109(12): 4178–4219.

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
Media: Bloomberg, The New York Times, The NBER Digest, The Wall Street Journal, The Washington Post, [More coverage]
Eprints: NBER Working Paper | NIH Public Access
Winner: NIHCM Foundation Research Award
Abstract | Manuscript | Article | Citation | Appendix | Data and Code | 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.

Jones, Damon, David Molitor, and Julian Reif. 2019. “What do Workplace Wellness Programs do? Evidence from the Illinois Workplace Wellness Study.” The Quarterly Journal of Economics, 134(4): 1747–1791.

The Local Influence of Pioneer Investigators on Technology Adoption: Evidence from New Cancer Drugs
With Leila Agha
The Review of Economics and Statistics, March 2018
Eprints: NBER Working Paper | NIH Public Access
Abstract | Manuscript | Article | Citation | Appendix | Data and Code 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.

Agha, Leila, and David Molitor. 2018. “The Local Influence of Pioneer Investigators on Technology Adoption: Evidence from New Cancer Drugs.” The Review of Economics and Statistics, 100(1): 29–44.

The Evolution of Physician Practice Styles: Evidence from Cardiologist Migration
American Economic Journal: Economic Policy, February 2018
Eprints: NBER Working Paper | NIH Public Access
Abstract | Manuscript | Article | Citation | Appendix | Data and Code 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.

Molitor, David. 2018. “The Evolution of Physician Practice Styles: Evidence from Cardiologist Migration.” American Economic Journal: Economic Policy, 10(1): 326–56.

Association between rainfall and diagnoses of joint or back pain: retrospective claims analysis
With Anupam Jena, Andrew Olenski, and Nolan Miller
BMJ, December 2017 (Editor's choice)
Media: Harvard Medical School News, The New York Times, USA Today
Eprints: NIH Public Access
Abstract | Article | Citation

Objective To study the relation between rainfall and outpatient visits for joint or back pain in a large patient population.

Design Observational study.

Setting US Medicare insurance claims data linked to rainfall data from US weather stations.

Participants 1 552 842 adults aged ≥65 years attending a total of 11 673 392 outpatient visits with a general internist during 2008–12.

Main outcome measures The proportion of outpatient visits for joint or back pain related conditions (rheumatoid arthritis, osteoarthritis, spondylosis, intervertebral disc disorders, and other non-traumatic joint disorders) was compared between rainy days and non-rainy days, adjusting for patient characteristics, chronic conditions, and geographic fixed effects (thereby comparing rates of joint or back pain related outpatient visits on rainy days versus non-rainy days within the same area).

Results Of the 11 673 392 outpatient visits by Medicare beneficiaries, 2 095 761 (18.0%) occurred on rainy days. In unadjusted and adjusted analyses, the difference in the proportion of patients with joint or back pain between rainy days and non-rainy days was significant (unadjusted, 6.23% v 6.42% of visits, P<0.001; adjusted, 6.35% v 6.39%, P=0.05), but the difference was in the opposite anticipated direction and was so small that it is unlikely to be clinically meaningful. No statistically significant relation was found between the proportion of claims for joint or back pain and the number of rainy days in the week of the outpatient visit. No relation was found among a subgroup of patients with rheumatoid arthritis.

Conclusion In a large analysis of older Americans insured by Medicare, no relation was found between rainfall and outpatient visits for joint or back pain. A relation may still exist, and therefore larger, more detailed data on disease severity and pain would be useful to support the validity of this commonly held belief.

Jena Anupam B, Olenski Andrew R, Molitor David, Miller Nolan. 2017. “Association between rainfall and diagnoses of joint or back pain: retrospective claims analysis.” BMJ, 359: j5326.

Work in Progress

A Causal Concentration-Response Function for Air Pollution: Evidence from Wildfire Smoke
With Nolan Miller and Eric Zou
Peer Effects in the Workplace: Evidence from the Illinois Workplace Wellness Study
With Damon Jones and Julian Reif
Habit Formation in Health Behaviors: Evidence from the Illinois Workplace Wellness Study
With Damon Jones and Julian Reif

Other Writing

Air pollution and the labor market
With Mark Borgschulte and Eric Zou
IZA World of Labor, November 2022
The Illinois Workplace Wellness Study: Reply to Dr. Goetzell
With Damon Jones and Julian Reif
American Journal of Health Promotion, February 2020