Association for Public Policy Analysis & Management

Congestion of urbanized centers is a trademark accompanies of economic development across the globe. These economic forces pose a challenge with respect to environmental conditions and, therefore, welfare for populations in those areas. While empirical evidence has helped shape environmental regulation in developed nations, there is a scarcity of evidence to inform policy-makers in the developing world. In this paper, we focus on air pollution and undertake a causal inference study of its impacts on the health of infants in utero and soon after birth. We take advantage of the meteorological phenomenon of thermal inversion which in urban areas arguably exogenously lock pollutants closer to the ground. By employing detailed data from birth and health system utilization records around the metropolitan area of Sao Paulo, Brazil between 2002 and 2009 we detail cumulative effects of air pollution on infants’ health across different socio-economic strata. We also interact these thermal inversions with congestion data, license-plate-based circulation restriction policies for cars and trucks, and changes in public transportation supply and prices. Capitalizing on linked confidential data we are able to assess morbidity and mortality using mother fixed effects in our preferred specification. Our preliminary results confirm a positive relationship between thermal inversions and several air pollutants and suggest that exposure during pregnancy to thermal inversions has a large negative effect on health at birth and on infant mortality. Moreover, exposure to thermal inversions during time in uteroexacerbates the negative health effects of air pollution shocks during the first years of life.