In an exchange economy under uncertainty with two periods, one physical good, and finitely many states of the world, we show that for every (complete or incomplete) market span there exists a sequence of securities such that if they are introduced into markets one by one, the prices of any...

The paper analyzes a two period general equilibrium model with individual risk, aggregate uncertainty and moral hazard. There is a large number of households, each facing two individual states of nature in the second period. These states differ solely in the household's vector of initial...

This paper defines and studies optimality in a dynamic stochastic economy with finitely lived agents, and investigates the optimality properties of an equilibrium with or without sequentially complete markets. Various Pareto optimality concepts are considered, including interim and ex ante...

The stationary sunspot equilibria of a simple OLG economy with heterogeneous agents areconsidered. These equilibria are known to be suboptimal. The focus of the paper is on the efficacy,based on welfare economic considerations and informational requirements, of government policy insuch an...

This paper argues that the introduction of a short-sale constraint in the Arrow-Radner framework invalidates standard definitions of complete and incomplete markets. Two threshold values with familiar properties arise in this constrained set-up. If short sales are not allowed on some security,...

We study competitive equilibrium in sequential economies under limited commitment. Default induces permanent exclusion from financial markets and endogenously determined solvency constraints prevent debt repudiation. Our analysis shows that such an enforcement mechanism is essentially fragile,...

I provide a complete characterization of equilibrium with risk of default in sequential economies under uncertainty. Default induces permanent exclusion from financial markets and not-too-tight solvency constraints prevent debt repudiation at equilibrium. The method of analysis relies on a...

In this paper, we consider economies with (possibly endogenous) solvency constraints under uncertainty. Constrained inefficiency corresponds to a feasible redistribution yielding a welfare improvement beginning from every contingency reached by the economy. A sort of Cass Criterion (Cass (1972))...