An analysis of the dual problem described by Ronn (1987) reveals that it provides a powerful and easily interpretable test for the hypothesis of a single class of marginal investors, including models of equilibrium based on a “representative tax bracket.” When Ronn's empirical tests are...

The primary objective of this paper is to derive a multi-factor equilibrium model using a mean-variance approach. The results of this derivation provide greater insight into the nature of the resulting factors than does APT. There are several important implications for empirical tests of any <italic>a...</italic>