Ž . Resource and Energy Economics 20 1998 327–343 Empirical evidence of advances in scrubber technology Allen S. Bellas ) UniÕersity of Washington, Seattle, WA 98195, USA Seattle UniÕersity, Seattle, WA, USA Received 2 December 1996; revised 25 August 1997; accepted 29 August 1997 Abstract Ž . Flue gas desulfurization FGD units have been employed at US power plants for approximately 25 years to control sulfur dioxide emissions. Although it might be hoped that Ž FGD technology would have improved over that period, theoretical work e.g., Downing w and White Downing, P.B., White, L.J., 1986, Innovation in pollution control, J. Environ. x w Econ. Manage., 13, 18–29 , and Milliman and Prince Milliman, S.R., Prince, R., 1989, Firm incentives to promote technological change in pollution control, J. Environ. Econ. x. Manage., 17, 247–265 has shown that the type of regulation generally favored in the US Ž . direct regulation of emissions levels provides poor incentives for technological improve- ments. Data on the design, performance and costs of FGD units at coal burning plants in the US are used to estimate a model of FGD costs and tests are performed in an attempt to determine whether progress has occurred. Results suggest that no significant progress has occurred in abatement technology, although costs of operating particular units at plants to tend to decrease over the lifetime of the unit. q 1998 Elsevier Science B.V. All rights reserved. PACS: L5; L9; O3; Q2 Keywords: Pollution; Control; Technology; Empirical; Coal ) Corresponding author. Department of Economics, Box 353330, University of Washington, Seattle, WA 98195, USA. Tel.: q1-206-543-5955; e-mail: bellas@u.washington.edu 0928-7655r98r$ - see front matter q 1998 Elsevier Science B.V. All rights reserved. Ž . PII: S0928-7655 97 00039-0