^*John F. Stewart, Department of Economics, University of North Carolina, participated as an expert witness m the case described in this paper. The views expressed in the paper are the authors alone and do not necessarily reflect the opinions of the Federal Trade Commission or any of its staff. The assistance of Paul Davis, Truett Honeycutt, Harold Kirtz and Douglas Brown of the Federal Trade Commission Atlanta office, and George Birrell are gratefully acknowledged Useful comments on earlier drafts were provided by Helen Tauchen, Mark Stegeman, and an anonymous referee The research assistance of Stephen O'Brien is also acknowledged.