Necessary and Sufficient Condition for the Existence of Equilibrium in Finite Dimensional Asset Markets with Short-Selling and Preferences with Half-Lines
1 : Maître de conférences
University of Evry-Val-d'Essonne
We consider a pure exchange asset model with a finite number of agents and a finite number of states of nature where short sells are allowed. We present the definition of weak no-arbitrage price, a weaker notion of no-arbitrage price than the one of Werner, and prove that if the utility functions satisfy the maximal and closed gradients conditions we propose in this paper, then there exists an equivalence between existence of a general equilibrium and existence of a price which is weak no-arbitrage price for all the agents.