Sources of Emission Reductions: Evidence from U.S. SO2 Emissions from 1985 through 2002

This paper, published by Massachusetts Institute of Technology's Center for Energy and Environmental Policy Research, describes database studies that have examined where the greatest emission reductions in sulfur dioxide have occurred over the past twenty years. Specifically, the paper examines whether reductions have come from retrofits of existing power generation plants, or replacement of old plants with new generating capacity. The paper finds that the greatest reductions have been gained through plant retrofits, though new plants have also displaced potential emissions from the generation facilities they replaced.