Accurate estimates of pollution abatement costs are crucial elements of any rational effort to set or evaluate environmental policies. One of the primary sources of this information in the United States has been the Bureau of the Census (BOC) Pollution Abatement Costs and Expenditures (PACE) survey, which collected annual establishment-level data on abatement costs for most years between 1972 and 1994. After a five-year lapse, the PACE survey was restarted in 2000, collecting 1999 data. Yet as firms have turned to more comprehensive abatement strategies involving process and design changes, pollution prevention, and recycling, the PACE survey has faced a number of problems that limit its ability to accurately measure abatement costs. At the same time, both national and international interest in understanding the true costs of environmental protection has grown, along with the complexity of the research and policy issues currently under discussion. There is now widespread interest in redesigning the PACE survey to improve its usefulness to policymakers as well as to researchers. In March 2000, Resources for the Future (RFF) convened an expert workshop to consider a wide range of issues relevant to future PACE surveys. This report describes the workshop and derives a number of conclusions based on discussions at the workshop.