This paper analyzes the variety of optimal screening contracts in a relatively simple multidimensional framework a` la Armstrong and Rochet (1999), when only three types of agents are present. It is shown, among other things, that the well known principle in optimal contract theory of `no...

The Weak Weak Axiom (WWA) for the aggregate excess demand function ensures uniqueness of equilibrium in regular economies. Jerison (1999) shows that the WWA holds if the excess demand satisfies the hypothesis of Nondecreasing Dispersion of Excess Demand (NDED). This note offers a new hypothesis...

The paper shows that any sigma-transitive preference can be extended to a complete preference preserving sigma-transitivity. The result has potential applications to the theory of choice and specifically to revealed preference theory.