Title IV of the 1990 Clean Air Act Amendments introduced a cap-and-trade system for sulfur dioxide emissions from electric power plants in the United States. This paper analyzes the effects of that regulatory change on the prices charged by the two railroads that hauled low-sulfur coal east from Wyoming.

We estimate the effect of the tradeable permits regime by comparing prices at affected plants (called “Table A plants”) before and after the allowance market took effect, and by comparing prices at those plants to prices at unaffected plants. We show that after Title IV took effect, the delivered price of low-sulfur coal — controlling for the minemouth price of coal and the variable cost of transportation — rose at Table A plants within approximately 1000 miles of the Powder River Basin, and fell at Table A plants located further away. This shift in the delivered price schedule of PRB coal is consistent with a theoretical model of the effects of emissions regulation on demand for low-sulfur coal, and the corresponding optimal pricing strategy by a carrier with market power. Our results suggest that the railroads were able to price discriminate among power plants on the basis of the environmental regulations governing the plants.

This paper uses data from the U.S. electric power industry to explore the strategic responses of regulated firms to government enforcement. We focus on the enforcement of New Source Review, a provision of the Clean Air Act that imposes stringent emissions limitations on substantially modified older power plants. Starting in late 1999, the EPA sued the owners of 46 power plants for NSR violations. This paper explores how electric utilities responded to both the perceived threat of future action, and the action itself. We find that the threat of action did have a significant effect on emissions: plants that were likely to be named in the lawsuits (as determined by our discrete choice model of the lawsuit decision) reduced their emissions by about 17 percent on the eve of the lawsuits. After the lawsuits, we find no significant difference between those plants sued and other relatively dirty coal-fired power plants.