Environment and Health

Associations Between Vehicle Miles Traveled and Ambient Air Pollution at Regulatory Monitoring Sites: A Natural Experiment Using the COVID-19 Shutdown

Transportation planners calculate vehicle miles traveled (VMT) to forecast roadway usage and inform policy decisions. However, the relationship between VMT and ambient air pollution is not fully understood. In this analysis, we use proprietary smartphone sensing data with VMT calculations to examine the impact of VMT on ambient air pollution during the decline in vehicle usage from the COVID-19 shutdown. We aim to determine how VMT change contributes to change in NO2, O3, and PM2.5 concentrations and at what spatial scale these changes occur.

Health Effects Institute (HEI): Congestion, Highway Improvement Projects, and Infant Health

While billions of dollars are spent each year on highway infrastructure investments to reduce traffic congestion (i.e., improvement projects), there is limited evidence evaluating the success of these projects with respect to changing exposure to traffic-related air pollution for communities nearby. This paper evaluates the overall and distributional health effects of highway infrastructure investments to reduce traffic congestion on infant health for mothers living near these roadways. Existing research explores the cost associated with roadway volume and determinants of volume such as tolling, but this paper is the first to estimate the effect of construction projects that reduce roadway congestion (measured as both volume and delay) on infant health.

Health Effects Institute (HEI): Changes in Traffic Congestion and Air Pollution Due to Major Roadway Infrastructure Improvements

Traffic-related air pollution (TRAP) is an established health hazard, and roadway construction has the potential to affect TRAP by relieving congestion. The relationship between roadway construction and congestion is of policy importance, but few studies examine it using large samples of construction projects and detailed traffic and air pollution data. We create a dataset of construction projects in Texas and link them to data on air pollution and three variables operationalizing congestion: average annual daily traffic (AADT), AADT per lane, and delay in hours. We use difference-in-difference methods to estimate the effect of widening and intersection improvements on congestion and air pollution.

Health Effects Institute (HEI): Housing Price Changes in Response to Congestion Projects

Using a quasi-experimental design, this study focuses on how changes in air quality through reductions in traffic congestion affect housing prices. We use roadway construction projects to identify exogenous shocks to local traffic trends. We find a limited response of house prices to nearby construction projects. This suggests that the positive health effects of the associated pollution reductions are not salient to home buyers, or may be offset by other negative externalities associated with the construction projects.

Hazardous Waste Clean-Ups

Focusing on cleanups of hazardous waste sites under the Resource Conservation & Recovery Act (RCRA), this study examines water quality, housing prices, & infant health after the cleanups to evaluate the program.

Read our NBER working paper on Hazardous Waste Clean-Ups.

Listen to a podcast episode about this work.

Drinking Water Contamination and Birth Outcomes

Using new estimates from drinking water estimates, we estimate the effects of drinking water contamination on public health in the United States using difference-in-differences empirical designs. We measure public health and water contamination using birth records and sampling results, respectively, using large administrative datasets. This work informs public drinking water regulation by proposing a simplification of consumer confidence reports.

Leasing and Environmental Justice

Do disadvantaged families sign fewer beneficial lease clauses when they negotiate leases? Do disadvantaged families that do not hold leases live near shale wells that are subject to fewer potentially health-protective lease clauses? Do health-protective lease clauses moderate the relationship between proximity to wells and infant birth outcomes?

Read our NBER working paper on Leasing and Environmental Justice.

Fracking and Environmental Justice

Shale gas development has been linked to air pollution as well as adverse education outcomes. This study assesses the proximity of shale gas wells with schools in the US. Our novel dataset, linking wells, waste, leasing, school districts and school locations with demographic information of students attending those schools allow for a unique assessment of environmental justice.

Environmental Justice in Oil and Gas Regulatory Compliance

We examine the consequences for environmental justice of systems where citizen complaints play a role in when and where regulations are enforced. To do so, we present a game based on matching pennies played between the regulator and firm, with the neighbors’ involvement, and derive comparative static predictions. We examine evidence for our model in the context of Pennsylvanian oil and gas wells. We find that complaints are informative, and that wells operating near poorer residents are inspected less often yet are more likely to be caught violating regulations conditional on being inspected.