Ce travail est constitue de deux parties. Dans un premier temp, nous etudions un modele ou les actifs sont des projets d'investissements decrits par leurs flux. Ceux-ci sont modelises par des processus stochastiques dont la dynamique est decrite par un arbre binomial. Les investissements ont la...

We present a version of the APT based on an asset index set of an arbitrary infinite cardinality. Under assumptions due to Ross and Chamberlain-Rothschild, we shhow that in the absence of gains from asymptotic arbitrage, the square of the deviations of the individual rates of return from a...

In this paper, we first give a direct proof of the existence of Edgeworth equilibria for exchange economies with consumption sets which are (possibly) unbounded below. The key assumption is that the individually rational utility set is compact. It is worth noticing that the statement of this...

In frictionless securities markets, the characterization of the no arbitrage condition by the existence of equivalent martingale measures in discrete time is known as the fundamental Theorem of Asset Pricing. In the presence of convex constraints on the trading strategies, we extend this theorem...

Dans ce travail, nous proposons un cadre general pour les modeles discrets et finis. Tout d'abord, nous montrons un resultat d'absence d'arbitrage. Puis, nous l'appliquons afin de retrouver les resultats deja connus sur les couts de transaction et les contraintes de vente a decouvert, pour des...

We provide a proof of the existence of a (quasi-)equilibrium in an exchange economy with short selling when the preference relations of the investors are represented by a partial preorder, a setting which encompasses the case of preference relations derived from a utility function. A second...