Dirty density: Air quality and the density of American cities

We study the effect of urban density on exposure city dwellers to air pollution using data from United States system. Exploiting geological features instrument for density, we find an economically and statistically significant pollution-density elasticity 0.14. assess health implications these estimates that increased in average leads sizeable mortality costs. Our findings highlight possible trade-off between reducing global greenhouse gas emissions, which is associated with denser cities according prior empirical research, preserving local quality human within cities.