An agency relationship arises when one party, the agent, takes actions on behalf of another party, a principal. The theory of agency was first developed in different contexts by Robert Wilson (1968, 1969), A. Michael Spence and Richard Zeckhauser, and the author (1973, 1974), and has been extended in a number of different directions. Steven Shavell, for example, has examined moral hazard issues associated with imperfectly monitoring the agent's effort and Milton Harris and Artur Raviv have looked at optimal contract structures. This paper takes up some different issues motivated by the desire to study the qualitative properties of equilibrium in markets for agents.