Voluntary Compliance, Pollution Levels, and Infant Mortality in Mexico

The increasing body of evidence from high income countries linking pollution to health outcomes (Ken Chay and Michael Greenstone 2003; Janet Currie and Matthew Neidell 2004), has raised concerns about the health impact of adverse air quality in developing countries, where, in general, environmental regulation is less stringent and health monitoring and treatment are less accessible. These concerns have, in turn, encouraged consideration of the effectiveness of alternative mechanisms for improving air quality while limiting the adverse impact on economic growth. However, the analysis of both the effects of pollution on health and the effectiveness of pollution abatement policies faces particular empirical challenges in low- and middle-income contexts, given the scarcity of reliable measures of pollution concentrations. The primary source of good quality data on air quality, ground monitoring, tends to be limited to larger metropolitan areas with monitors placed at sentinel sites that may or may not yield a representative picture of population exposure. This paper calls attention to, and makes use of, newly available procedures for extracting measures of air quality from satellite imagery. In particular, satellite-based measures of aerosol optical depth (AOD) are used to obtain estimates of air quality for the whole Mexican territory at a detailed geographic scale, and these estimates are related to measures of participation in a voluntary certification program at the level of the county. The resulting estimates are then combined with estimates of the relationship between participation in the certification program and infant mortality due to respiratory causes to obtain a rough estimate of the relationship between air quality and infant health in Mexico.