This report was prepared as part of the Ohio River Basin Energy Study (ORBES), a multidisciplinary policy research program supported by the Environmental Protection Agency. The ORBES region covers all of Kentucky, most of West Virginia, southwestern Pennsylvania, and substantial portions of Illinois, Indiana and Ohio. Central Ohio is an area where the long-range transport of air pollutants is a problem, and a relatively small increase in pollution emitted from sources within the SMSA could cause the area to violate federal primary standards for sulfur dioxide and particulates. This report estimates the potential loss in economic product to the Columbus SMSA by calculating the difference in economic output between (1) the projected increase in potential output possible under existing air quality regulations without additional background pollution from new out-of-area fossil fuel power plants and (2) the projected increase in output possible when this additional source of pollution is taken into account. Estimated losses are provided for seven different ORBES scenarios.