Mountains of Evidence: The Effects of Abnormal Air Pollution on Crime

We find that PM2.5 air pollution increases crime in a city that ranks in the worst two percentiles worldwide for dirty winter air. Our identification strategy employs distinct geographic features of Almaty, Kazakhstan: cleaner mountain winds and frequent temperature inversions. Using a PPML control function approach, we estimate a PM2.5 elasticity of the expected crime rate more than four times as large as studies of cleaner cities. We identify effects of PM2.5 on robbery and high-stakes property crime. Our results support theory that air pollution induces both aggression and a disregard for consequences.