At a competitive equilibrium of an incomplete-markets economy agents’ marginal valuations for the tradable assets are equalized ex-ante. We characterize the finest partition of the state space conditional on which this equality holds for any economy. This leads naturally to a necessary and...

A speculative security is an asset whose payoff depends in part on a random shock uncorrelated with economic fundamentals (a sunspot) about which some traders have superior information. In this paper we show that agents may find it desirable to trade such a security in spite of the fact that it...

This paper studies the conditions for aggregation, portfolio separation and effective completeness of competitive allocations in general equilibrium models with incomplete markets where agents have general preference and endowment distributions. We show that these properties are distinct....

We prove that locally, Walras' law and homogeneity characterize the structure of market excess demand functions when financial markets are incomplete and assets' returns are nominal. The method of proof is substantially different from all existing arguments as the properties of individual demand...

In this paper we investigate the consequences of the firms' financial decisions in the framework of a perfectly competitive general equilibrium model with incomplete markets. When markets are complete or there are no derivative securities (such as options, forwards or futures) written on the...