This collection of essays honors David Cass on the 30th anniversary of his joining the faculty of the Department of Economics at the University of Pennsylvania. Prof. Cass's work has spawned a number of important lines of research in Economics, including the study of dynamic general equilibrium,...

In this paper we develop a differential technique for investigating the welfare effects of financial innovation in incomplete markets. Utilizing this technique, and after parametrizing the standard competitive, pure-exchange economy by both endowments and utility functions, we establish the...