Gray Matters: Fetal Pollution Exposure and Human Capital Formation

This paper examines the impact of fetal exposure to air pollution on 4th grade test scores in Santiago, Chile. We rely on comparisons across siblings which address concerns about locational sorting and all other time-invariant family characteristics that can lead to endogenous exposure to poor environmental quality. We also exploit data on air quality alerts to help address concerns related to short-run time-varying avoidance behavior, which has been shown to be important in a number of other contexts. We find a strong negative effect from fetal exposure to carbon monoxide (CO) on math and language skills measured in 4th grade. These effects are economically significant and our back of the envelope calculations suggest that the 50% reduction in CO in Santiago between 1990 and 2005 increased lifetime earnings by approximately 100 million USD per birth cohort.