Consumption externalities, rental markets and purchase clubs

Summary. A premise of general equilibrium theory is that private goods are rival. Nevertheless, many private goods are shared, e.g., through borrowing, through co-ownership, or simply because one persons consumption affects another persons wellbeing. I analyze consumption externalities from the perspective of club theory, and argue that, provided consumption externalities are limited in scope, they can be internalized through membership fees to groups. Two important applications are to rental markets and purchase clubs, in which members share the goods that they have individually purchased.Received: 2 June 2003, Revised: 8 March 2004, JEL Classification Numbers: D11, D62.This paper was supported by the U.C., Berkeley Committee on Research, and the Institute of Economics, University of Copenhagen. I am grateful to Birgit Grodal for her collaboration on the theory that underlies this paper, and for her helpful and motivating comments about these particular extensions. I also thank Hal Varian, Doug Lichtman, Steve Goldman, Karl Vind, anonymous referees, and members of the Berkeley Microeconomics Seminar for discussion.