This article compares two leading models of asset pricing: the capital asset pricing model (CAPM) and the arbitrage pricing theory (APT): I argue that while the APT is compatible with the data available for testing theories of asset pricing, the CAPM is not. In reaching this conclusion emphasis...

This paper presents a general model of the demand for differentiated products which has as special cases two popular models used to analyze welfare and competition in monopolistically competitive markets: the model of spatial competition and the symmetric aggregate benefit function approach. The...