Competitive Equilibrium with Asymmetric Information: an Existence Theorem for Numeraire Assets

Lionel De Boisdeffre (1, 2)

1 CES - Centre d'économie de la Sorbonne
2 CATT - Centre d'Analyse Théorique et de Traitement des données économiques

In [2], we had extended the classical concepts and arbitrage theory of symmetric information, to an asymmetric information model, which dropped Radner?s (1979) rational expectations' ?assumption. In [3], we showed how agents could infer enough information, in this model, to rule out arbitrage from markets. In [4], we extended to that model Cass?(1984) classical existence Theorem for nominal assets. Namely, we showed that existence of equilibrium was characterized by the generalized no-arbitrage condition introduced in [2], whether agents had symmetric or asymmetric information. We now display the same characteristic property for numeraire asset markets, and, thus, extend Geanakoplos-Polemarchakis?(1986) existence Theorem to the asymmetric information setting. Contrasting with Radner?s, these results show that symmetric and asymmetric information economies can be embedded into a common general equilibrium model, where they share similar properties.

Mots clés: General equilibrium; Asymmetric information; Arbitrage; Existence

Domaines: Economies et finances

Lionel De Boisdeffre. Competitive Equilibrium with Asymmetric Information: an Existence Theorem for Numeraire Assets. 2015. ⟨hal-01871572⟩