EPA has taken another step to improve environmental regulation by examining the process and factors that affect the estimated costs of regulations. The report, "Retrospective Study of the Costs of EPA Regulations: A Report of Four Case Studies" (August, 2014), discusses the factors that may account for differences between projected and actual regulatory costs and presents the findings of four case studies that attempt to assess compliance cost retrospectively. As the report shows, the retrospective assessments were challenging to conduct and were often limited by a paucity of comprehensive cost information on treatment technologies and mitigation strategies. Disentangling the expenditures made expressly for required pollution control from other investments made at the same time was a challenge for several of the case studies. While informative, the added evidence provided by these four case studies is insufficient to draw broad conclusions about EPA cost estimation practices.

EPA’s Science Advisory Board (SAB) provided an independent peer review of an earlier draft of this report. This report incorporates many of its recommendations to EPA on how best to move forward with retrospective cost analyses given the limited information available.

The report represents the Agency’s latest action to strengthen environmental regulation under the "Improving Regulation and Regulatory Review" Executive Order.

You can download the full report here: Retrospective Study of the Costs of EPA Regulations: A Report of Four Case Studies