Welfare Measurement and Representative Consumer Theory V. Kerry Smith Department of Economics Duke University Durham NC 27708 and Resources for the Future Washington, D.C. Roger Von Haefen Center for Environmental and Resource Economics Duke University Durham, NC 27708 Abstract This paper generalizes results from Anderson, De Palma, and Thisse [1992] linking individual random utility and aggregate representative individual demand models, to consider a comparable relation for the willingness to pay functions for quality attributes of marketed goods. It also suggests how the logic can be used to describe links between choice occasion and aggregate models (across occasions) for an individual. Key Words: Willingness to Pay, RUM, Aggregation JEL Classification No(s): DG1, Q2 Address for Correspondence: V. Kerry Smith Department of Economics Duke University Box 90097 Durham NC 27708 Fax: (919) 684-8741