Working Paper: NBER ID: w10053
Authors: Kenneth Y. Chay; Michael Greenstone
Abstract: We examine the effects of total suspended particulates (TSPs) air pollution on infant health using the air quality improvements induced by the 1970 Clean Air Act Amendments (CAAA). This legislation imposed strict regulations on industrial polluters in nonattainment' counties with TSPs concentrations exceeding the federal ceiling. We use nonattainment status as an instrumental variable for TSPs changes to estimate their impact on infant mortality changes in the first year that the 1970 CAAA was in force. TSPs nonattainment status is associated with sharp reductions in both TSPs pollution and infant mortality from 1971 to 1972. The greater reductions in nonattainment counties near the federal ceiling relative to the attainment' counties narrowly below the ceiling suggest that the regulations are the cause. We estimate that a one percent decline in TSPs results in a 0.5 percent decline in the infant mortality rate. Most of these effects are driven by a reduction in deaths occurring within one month of birth, suggesting that fetal exposure is a potential biological pathway. The results imply that roughly 1,300 fewer infants died in 1972 than would have in the absence of the Clean Air Act.
Keywords: Air Quality; Infant Mortality; Clean Air Act
JEL Codes: I12; I16; Q25
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| nonattainment status (Q52) | TSP pollution (Q53) |
| TSP pollution (Q53) | infant mortality rate (J13) |
| nonattainment status (Q52) | infant mortality rate (J13) |
| 1970 CAAA regulatory measures (Q52) | TSP pollution (Q53) |
| 1970 CAAA regulatory measures (Q52) | infant mortality rate (J13) |
| TSP pollution (Q53) | infant mortality within one month of birth (J13) |