When EPA assesses the costs and benefits of environmental regulations, it typically looks at direct health impacts resulting from exposure to pollutants. According to a recent National Bureau of Economic Research working paper by Evan Herrnstadt and Erich Muehlegger, EPA may need to start assessing the costs of another set of pollution impacts – violent crime. In Air Pollution and Criminal Activity: Evidence From Chicago Microdata, Herrnstadt and Muehlegger conclude that exposure to air pollution increases violent crime.
It’s a fascinating article. The simple summary is that Herrnstadt and Muehlegger looked at local crime data in Chicago and compared crime rates upwind and downwind of the major interstates in Chicago. They found that:
The downwind side of interstates experience 2.2 percent more violent crimes than when the wind is blowing in the opposite direction.
That may not seem like a lot, but it adds up to a substantial amount of additional crime. While the authors only did “back-of-the-envelope” estimates of the cost of the additional crime, it certainly seems potentially substantial enough for EPA to consider in its cost-benefit analyses.
The work is fairly intricate and too complicated to explain here. (It’s also been more than 30 years since I performed a regression analysis.) However, they seem to have made some fairly rigorous efforts to control for the obvious important factors. It will be interesting to see if this result is replicated elsewhere. I wouldn’t be surprised if it is.
Next time you are out for a walk on a hot sunny summer day and you are feeling annoyed and short-tempered, consider that it may not just be the heat (or the humidity), it may also be the pollution.