The impact of air pollution on infant mortality: Evidence from geographic variation in pollution shocks induced by a recession

The 1981-1982 recession induced substantial variation across sites in air pollution reductions. This is used to estimate the impact of total suspended particulates (TSPs) on infant mortality. We find that a 1-percent reduction in TSPs results in a 0.35 percent decline in the infant mortality rate at the county level, implying that 2500 fewer infants died from 1980-1982 than would have in the absence of the TSPs reductions. Most of these effects are driven by fewer deaths occurring within one month of birth, suggesting that fetal exposure is a potential pathophysiologic mechanism. The analysis also reveals nonlinear effects of TSPs pollution and greater sensitivity of black infant mortality at the county level. Importantly, the estimates are stable across a variety of specifications.