Hold your breath! Air pollution and cognitive performance in Colombia

Air pollution is a known health hazard, and evidence of negative effects beyond the health dimension is rapidly emerging. This paper studies the effect on one non-health dimension, namely cognitive performance. It exploits exogenous variation in exposure to air pollution during secondary school exams and estimate the contemporaneous effect on students’ cognitive performance in Colombia between 2012 and 2018. The results indicate that exposure to air pollution on the day of the exam itself negatively impacts students’ performance. Using variation in wind direction as an instrument for air pollution, I find that a one standard deviation increase in air pollution reduces overall test scores by 0.05 standard deviations. For students who continue to tertiary education, there is no evidence that this distorted signal of their cognitive abilities at the secondary school exam translates into differences in college attendance, as proxied by college graduation rates.