Energy Studies Review, Vo!. ii, No. i. 2003 pp 76 - 92 ESTIMATING MARGINAL ABATEMENT COSTS OF SPM: AN APPLICATION TO THE THERMAL POWER SECTOR IN INDIA Surender Kumar & D. N. Rao ABSTRACT This paper provides estimates of firm specific marginal abatement costs of suspended particulate matters (SPM) for the thermal power sector in India. To derive these costs, the duality of the output distance function and the revenue function is used. This study uses the output distance function framework to estimate marginal abate- Surender Kurnar is a Lecturer in Economics at Arya College, Panipat 132 103 India. D.N. Rao is a Professor in Economics at the Centre for Economic Studies & Planning at the School a/Social Sciences. Hawaharlal NehlY University, New Delhi JJ0067. India. Email: dnrao@vsnl.com or surinder_bansal@yahoo.com Surender Kumar is presently a visiting scholar at the Department 0/ Agricultural and Consumer Economics, University of Illinois at Urbana-Champaign under the World BankAided Environmental Management Capacity Building Project in India. This paper forms part of the Ph.D. thesis submitted to the Jawaharlal Nehru University New Delhi entitled 'Economic Evaluation of Development Projects: A Case Analysis ofEnvironmental Health Implications of the Thermal Power Sector in India '. We are grateful to two anonymous referees and the editor of thisjournal for vely useful comments on an earlier draft of this paper.