Elena Meschi (University of Milano-Bicocca)
Simone Ferro and Caterina Pavese
This paper examines the short-term effects of air pollution, specifically fine particulate matter (PM2.5), on the cognitive performance of primary school students in Italy, a country where pollution levels frequently exceed WHO-recommended thresholds. Leveraging longitudinal administrative data from standardized national tests (INVALSI) and high-resolution air quality data at the municipality level, we exploit day-to-day variation in pollution exposure within municipalities to identify causal effects. Our empirical strategy includes a rich set of fixed effects and an instrumental variable approach using planetary boundary layer height to address potential endogeneity. We find that higher PM2.5 levels are significantly associated with lower student test scores. A one microgram per cubic meter increase in PM2.5 results in a 0.14-point drop in test scores, equivalent to a 0.35% decline in standard deviation. The negative impact is especially pronounced for reasoning-intensive questions, suggesting that air pollution primarily impairs cognitive processes requiring sustained attention and higher-order thinking. Interestingly, multiple-choice questions are more affected than open-ended ones, likely due to increased cognitive load associated with processing options - an effect consistent with the "paradox of choice" literature. Moreover, our results indicate that air conditioning in the schools can buffer the detrimental effects of pollution on academic performance