Kevin Lewis

November 18, 2020

The Effect of Leaded Gasoline on Elderly Mortality: Evidence from Regulatory Exemptions
Alex Hollingsworth & Ivan Rudik
American Economic Journal: Economic Policy, forthcoming


Leaded gasoline is still used globally for aviation and automotive racing. Exploiting regulatory exemptions and a novel quasi-experiment, we find that leaded gasoline use in racing increases ambient lead, elevated blood lead rates, and elderly mortality. The mortality estimates indicate that each gram of lead added to gasoline exceeds $1,100 in damages. Our setting allows us to rule out potential confounders, such as correlated pollutants or socioeconomic status. We provide the first causal estimates linking adult mortality to leaded gasoline, highlight the value of banning on-road leaded gasoline, and present policy-relevant cost estimates at the lowest ambient levels to date.

When Externalities Collide: Influenza and Pollution
Joshua Graff Zivin et al.
NBER Working Paper, October 2020


Influenza and air pollution are significant public health risks with large economic consequences shared across the globe. The common etiological pathways through which they harm health present an interesting case of compounding risk via interacting externalities. Using regional and temporal variation in pollution and disease transmission, we find exposure to more air pollution significantly increases influenza hospitalizations. By exploiting the random deviations in influenza vaccine effectiveness over time, we show high influenza vaccine effectiveness neutralizes this relationship. This suggests seemingly disparate policy actions of pollution control and expanded vaccination provide greater returns than found when studied in isolation.

Impact of low-level fine particulate matter and ozone exposure on absences in K-12 students and economic consequences
Daniel Mendoza et al.
Environmental Research Letters, forthcoming


High air pollution levels are associated with school absences. However, low level pollution impacts on individual school absences are under-studied. Understanding the variability of pollution at individual schools within an urban region could improve school recess decisions, better identify local pollution sources, and improve local economic impact assessments by providing granular information relevant to specific schools. We modelled PM2.5 and ozone concentrations at 36 schools from July 2015 to June 2018 using data from dense research grade and regulatory sensor networks. We used a generalized estimating equations model to retrospectively estimate rate ratios for association between outdoor pollutant concentrations and daily school absences at each school. We estimated lost school revenue, productivity, and family economic burden. PM2.5 and ozone concentrations and absence rates vary across the School District. Pollution exposure was associated with a rate ratio as high as 1.02 absences per µg/m3 and 1.01 per ppb increase for PM2.5 and ozone, respectively. Significantly, even PM2.5 and ozone exposure below the air quality index breakpoints for good air quality (< 12.1 µg/m3 and < 55 ppb, respectively) was associated with positive rate ratios of absences: 1.04 per µg/m3 and 1.01 per ppb increase, respectively. Granular local measurements enabled demonstration of air pollution impacts that varied between schools and were undetectable with averaged pollution levels. Reducing pollution by 50% would save $426,000 per year districtwide. Pollution reduction benefits would be greatest in schools located in socioeconomically disadvantaged areas. Heterogeneity in exposure, disproportionately affecting socioeconomically disadvantaged schools, points to the need for fine resolution exposure estimation. The economic cost of absences associated with air pollution is substantial even excluding indirect costs such as hospital visits and medication. These findings may help elucidate the differential burden on individual schools and inform local decisions about recess and regulatory considerations for localized pollution sources.

Going Beneath the Surface: Petroleum Pollution, Regulation, and Health
Michelle Marcus
American Economic Journal: Applied Economics, forthcoming


This paper quantifies the health impacts of petroleum leaks from underground storage tanks, the effectiveness of tank regulation, and the role of information as a policy tool in the same setting. Exposure to a leaking underground storage tank during gestation increases both the probability of low birth weight and preterm birth by 7-8 percent. Compliance with regulations requiring the adoption of preventative technologies mitigated the entire effect of leak exposure on low birth weight, and information increased avoidance and moving among highly educated mothers. Back-of-the-envelope calculations suggest the health benefits of preventative regulations exceed the upgrade cost to facilities.

The ESG-Innovation Disconnect: Evidence from Green Patenting
Lauren Cohen, Umit Gurun & Quoc Nguyen
NBER Working Paper, October 2020


No firm or sector of the global economy is untouched by innovation. In equilibrium, innovators will flock to (and innovation will occur where) the returns to innovative capital are the highest. In this paper, we document a strong empirical pattern in green patent production. Specifically, we find that oil, gas, and energy producing firms – firms with lower Environmental, Social, and Governance (ESG) scores, and who are often explicitly excluded from ESG funds’ investment universe – are key innovators in the United States’ green patent landscape. These energy producers produce more, and significantly higher quality, green innovation. Our findings raise important questions as to whether the current exclusions of many ESG-focused policies – along with the increasing incidence of explicit divestiture campaigns – are optimal, or whether reward-based incentives would lead to more efficient innovative outcomes.

Metropolitan Manufacturing Decline and Environmental Inequalities in Industrial Air Pollution in the United States
Kevin Smiley
Sociological Inquiry, forthcoming


The changing manufacturing economy has received scant attention in research on environmental inequalities, even though manufacturing work in the United States has dropped precipitously since the mid‐20th century. I integrate manufacturing decline in metropolitan areas into the study of environmental inequality by using data on industrial air pollution in 1990, 2000, and 2010. I test to see if an indicator of change in the number of manufacturing workers in a metropolitan area from 1970 to each of the three study years is associated with more or less industrially produced toxic emissions. Findings show, somewhat counterintuitively, that metropolitan areas that have had a larger drop in manufacturing work are linked to greater industrial air pollution and that these findings hold in all U.S. regions except the West. Implications focus on how the indelible imprint of manufacturing history may condition contemporary pollution levels.

The End of the Express Road for Hybrid Vehicles: Can Governments’ Green Product Incentives Backfire?
Cheng He et al.
Marketing Science, forthcoming


In response to growing environmental concerns, governments have promoted products that are less harmful to the environment — green products — through various incentives. We empirically study the impact of a commonly used nonmonetary incentive — namely, the single-occupancy permission to high-occupancy vehicle (HOV) lanes — on green and non‐green product demand in the U.S. automobile industry. The HOV incentive could increase unit sales of green vehicles by enhancing their functional value through time saving. On the other hand, the incentive may prove counterproductive if it reduces the symbolic value (i.e., signaling a proenvironmental image) consumers derive from green vehicles. Assessing the effectiveness of green-product incentives is challenging, given the endogenous nature of governments’ incentive provisions. To identify the effect of the HOV incentive on unit sales of green and non‐green vehicles, we take advantage of HOV-incentive changes in two states, and we employ a multitude of quasi‐experimental methods using a data set at the county–model–month level. Unlike previous studies that only examine the launch of the HOV incentive and find an insignificant association between incentive launch and green-vehicle demand, we concentrate on its termination. We find that the termination of the HOV incentive decreases unit sales of vehicles covered by the incentive by 14.4%. We provide suggestive evidence that this significant negative effect of HOV-incentive termination is due to the elimination of the functional value the incentive provides: time saving. Specifically, we find that the negative effect is more pronounced in counties where consumers value time saving more (i.e., counties with a longer commute to work and higher income). Additionally, in line with prior literature, the launch of the HOV incentive is not found to have a significant effect on green-vehicle sales. Combined, our findings reveal that the effect of termination is not simply the opposite of that of launch, implying that governments’ green-product incentives could backfire.

How clean is “refined coal”? An empirical assessment of a billion-dollar tax credit
Brian Prest & Alan Krupnick
Energy Economics, forthcoming


US tax law provides nearly $1 billion annually in tax credits for “refined coal”, which is supposed to reduce local air pollution. Eligibility for the credit requires firms to demonstrate legally specified emissions reductions for three pollutants. Firms typically demonstrate eligibility through laboratory tests, but results from the lab can differ from those in practice. Using a nationally comprehensive boiler-level panel dataset, we find that emission reductions in practice are only about half of the levels required, and even then only arise when certain pollution controls are installed. We also show that the policy reduces social welfare, resulting in costs more than seven times the benefits, in part because of a “rebound” effect in which the subsidy increases coal use by extending the operational life of some coal plants. Because the tax credit is up for reauthorization in 2021, our work has immediate policy relevance.

High-resolution land value maps reveal underestimation of conservation costs in the United States
Christoph Nolte
Proceedings of the National Academy of Sciences, forthcoming


The justification and targeting of conservation policy rests on reliable measures of public and private benefits from competing land uses. Advances in Earth system observation and modeling permit the mapping of public ecosystem services at unprecedented scales and resolutions, prompting new proposals for land protection policies and priorities. Data on private benefits from land use are not available at similar scales and resolutions, resulting in a data mismatch with unknown consequences. Here I show that private benefits from land can be quantified at large scales and high resolutions, and that doing so can have important implications for conservation policy models. I developed high-resolution estimates of fair market value of private lands in the contiguous United States by training tree-based ensemble models on 6 million land sales. The resulting estimates predict conservation cost with up to 8.5 times greater accuracy than earlier proxies. Studies using coarser cost proxies underestimate conservation costs, especially at the expensive tail of the distribution. This has led to underestimations of policy budgets by factors of up to 37.5 in recent work. More accurate cost accounting will help policy makers acknowledge the full magnitude of contemporary conservation challenges and can help improve the targeting of public ecosystem service investments.


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