The effect of air pollution on exam performance: a case study using California public high schools

Abstract

The California High School Exit Exam (CAHSEE) and natural variation in ambient air quality are used to estimate the effect of pollution exposure on exam performance. Two regularly monitored air pollutants, particulate matter PM2.5 and PM10 are used as measures of air pollution. A negative relationship between particulate matter (PM2.5 and PM10) exposure and decreased exam performance is found. The results, from models using school and year fixed effects, suggest high levels (two standard deviation increases from the mean) of PM2.5 and PM10 on exam days cause declines in average exam performance of roughly 2-6% of a standard deviation compared to exams taken during less polluted days. The estimated magnitude of these findings is slightly smaller, but within bounds of similar studies from high school aged students in Israel and the United Kingdom. This relationship is found to hold for students from both high and low socio-economic status and is not statistically different between students who are White, African American, Hispanic or Latino or Asian although results are not robust to the inclusion of district-by-year time trends for the math section of the exam. These findings highlight that pollution reduction efforts could have positive impacts to students and schools that are not traditionally considered in cost/benefit analyses.