Does Regulation Matter?: Evaluating the Effects of State Air Pollution Control Programs

Air pollution emissions have declined significantly since the passage of the Clean Air Act (CAA) of 1970. Most policy observers have gone on to infer that the CAA has been the cause of these emissions reductions, though this claim has not received close empirical examination. In short, while air pollution emissions have been reduced, we do not know if these reductions are the result of pollution control regulation. In an effort to expand the study of policy outcomes, this article evaluates the effects various regulatory efforts have had on state air quality. The contention set forth here is that the strength of a state's air quality programs, along with other variables representing a political commitment to pollution control, have significant effects upon air pollutant emission levels. Using multiple regression and path analysis, these effects of regulation are apparent even when controlling for changes in economic activity, economic infrastructure, and fuel consumption, enabling us to conclude that in air pollution control, regulation does matter.