City Shape and Air Pollution

Air pollution has become an increasing health threat for the local population in many cities around the world. Using high resolution remote sensing data on nightlights and fine particulate matter (PM2.5) for the years 1998-2013, I study the contemporary nexus between city shape and air pollution in India. I find that the compactness of a city has statistically significant and negative effects on local air quality. The results are more pronounced in larger cities and robust with respect to different compactness measures. While geographic dispersion allows for more fresh air corridors, differences in commuting patterns could serve as an additional explanation. People in less compact cities are more likely to use public transport and thereby reducing the overall road traffic within cities translating into less pollution. However, the statistically significant effects do not translate into substantial changes in the relative risk of PM2.5-induced diseases.