Can voluntary pollution prevention programs fulfill their promises? Further evidence from the EPAʹs 33/50 Program

We examine incentives for firm participation in the EPAʹs 33/50 Program and the impact of this Program on firm emissions. We use a sample of manufacturing firms from 19 industry groups that were invited to participate in the Program in 1991. We find that while the Program may have attracted some of the most polluting firms, the decline in emissions observed between 1991 and 1995 was the result of an independent trend rather than a direct consequence of the Program as argued by an earlier study published in this Journal.