This article has developed a new model of welfare dynamics under imperfect information or imperfect competition by introducing a new concept of ‘inefficient welfare equilibrium’. It assumes that an economy can be split into two virtual parts. For one part the fundamental welfare theorems are...

We consider economies with incomplete markets, one good per state, two periods, t = 0; 1, private ownership of initial endowments, a single firm, and no assets other than shares in this firm. In Dierker, Dierker, Grodal (2002), we give an example of such an economy in which all market equilibria...

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...

In this paper, we consider economies with (possibly endogenous) solvency constraints under uncertainty. Constrained ine±ciency corresponds to a feasible redistribution yielding a welfare improvement beginning from ev- ery contingency reached by the economy. A sort of Cass Criterion (Cass [10])...

This paper argues that the introduction of a short-sale constraint in the Arrow-Radner frameworkinvalidates standard definitions of complete and incomplete markets. In this constrained set-up,two threshold values with familiar properties arise.The case of a zero short-sale bound set on some...

Pecuniary externalities have regained the interest of researchers as they seek policy interventions and regulations to remedy externality-induced distortions, e.g., balance sheet effects, amplifiers and fire sales. In this paper we go back to first principles and show how to design financial...

This paper studies a competitive general equilibrium model with default and endogenous collateralized contracts. The possibility of trade in spot markets creates externalities, as spot prices and the bindingness of collateral constraints interact. We propose a market based solution which...

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...

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...