The effects of air pollution on students’ cognitive performance: evidence from Brazilian university entrance tests

We examine the contemporaneous causal relationship between outdoor air pollution levels and student cognitive performance in Brazil’s nationwide university entrance examinations. Our analysis relies upon a unique and previously unexplored student-level data set allowing us to examine the effect of particulate matter (PM₁₀) on students’ scores. In our main specification we construct individual-level panel data for the 2 days of exams across 3 years and apply student fixed effects to address potential endogeneity concerns. In addition, we take advantage of plausibly exogenous spatial and temporal variation in PM₁₀ across municipalities in the states of Rio de Janeiro and São Paulo and utilize an instrumental variable approach based on wind direction. Our results suggest that air pollution negatively impacts the cognitive performance of students. We find suggestive evidence that boys may be more affected than girls, and less well-off exam takers at the bottom of the score distribution are more affected than their more privileged counterparts.