Can a low emission zone improve academic performance? Evidence from a natural experiment in the city of Madrid

-In late 2018, the government of Madrid instituted a low emission zone (LEZ) in the central district of the city, aiming primarily to alleviate traffic-related emissions and enhance air quality. Extensive research has documented the adverse effects of air pollution on academic performance. Consequently, the success of Madrid’s LEZ in reducing traffic-related emissions could potentially translate into improved performance among students schooled in the designated area. Through a difference-in-differences design, we demonstrate the policy's effectiveness in improving air quality during the four years following its implementation. Subsequently, we show a noteworthy increase of 0.17 standard deviations in the average EvAU scores (high-stakes examinations for university admittance) of high schools within the LEZ, a crucial advantage for gaining entry into the most competitive university programs. Importantly, our findings reveal positive spillover effects in the surroundings of the LEZ area and a larger effect the longer and earlier the exposure to cleaner air. In sum, our study offers compelling empirical evidence of the beneficial educational impacts resulting from the implementation of a low emission zone successful in improving air quality.