Pollution and Learning

ABSTRACT

We estimate the causal impact of air pollution on student learning using longitudinal PSAT data from over 16 million U.S. high school students who took the exam multiple times between 2000 and 2020. Our within-student design, combined with an instrumental variables strategy exploiting variation in wildfire smoke from distant fires, isolates plausibly exogenous changes in local PM2.5 concentrations. We find that exposure to moderately polluted days (8-12 ug/m3) during the school year significantly reduces academic performance, with IV estimates substantially larger than OLS. Effects are concentrated during the academic year rather than summer months, suggesting disruption to learning rather than cumulative health impacts. We document meaningful heterogeneity: students attending high-challenge schools and those with lower baseline achievement experience larger adverse effects. Our results demonstrate harmful impacts at pollution levels below proposed EPA standards, with important implications for environmental regulation and educational equity.

BIO

Patrick Behrer is an Economist on the Planet Research Team of the World Bank's Development Research Group. Behrer's work focuses on the economics of air pollution, climate change, and climate adaptation. His work has focused on the impacts of air pollution and climate change on human capital formation and the relationship between agriculture and air pollution. His work leverages big data from online and administrative sources and recent advances in satellite remote sensing technology. Prior to joining the World Bank in 2021, he was a post-doctoral fellow at the Center on Food Security and the Environment at Stanford University. He received his Ph.D. in 2020 from Harvard University in Public Policy.