This article proposes and evaluates four hypotheses about US pollution and environmental policy over the last half … century. First, air and water pollution have declined substantially, although greenhouse gas emissions have not. Second …, environmental policy explains a large share of these trends. Third, much of the regulation of air and drinking water pollution has …

We compare the spatial distribution of emissions from Southern California's pollution-trading program with that of a …

growing distributional concern that market forces could increase the pollution exposure gap between disadvantaged and other … communities by spatially reallocating pollution. We estimate how this "environmental justice gap" changed following the 2013 … critiques. Embedding a pollution transport model within a program evaluation framework, we find that while the EJ gap was …