We provide a discipline for belief formation through a model of subjective beliefs, in which agents hold strategic beliefs. More precisely, we consider beliefs as a strategic variable that agents can choose (consciously or not) in order to maximize their utility at the equilibrium. These...

In this paper, we show that behavioral features can be obtained at a group level when the individuals of the group are heterogeneous enough. Starting from a standard model of Pareto optimal allocations, with expected utility maximizers but allowing for heterogeneity among individual beliefs, we...

In this paper we analyse the risk attitude of a group of heterogenous agents and we develop a theory of comparative collective risk tolerance. In particular, we characterize how shifts in the distribution of individual levels of risk tolerance affect the representative agent's degree of risk...

This paper presents an equilibrium model in a pure exchange economy when investors have three possible sources of heterogeneity. Investors may dier in their beliefs, in their level of risk aversion and in their time preference rate. We study the impact of investors heterogeneity on the...

Standard models for fi…nancial markets are based on the simplifying assumption that trading orders can be given and executed in continuous time with no friction. This assumption is clearly a strong idealization of the reality. In particular, securities should not be described by a single price...

La modélisation et l'analyse des comportements individuels et collectifs vis-à-vis du risque est au coeur des problématiques de recherche de la chaire de la Fondation du Risque " Les particuliers face aux risques : analyse et réponse des marchés " créée grâce au soutien de Groupama....

Given exogenously the price process of some asets, we constrain the price process of other assets, which are characterised by their final pay-offs. We deal with an incomplete market framework in a discrete time model and assume the existence of the equilibrium. In this setup, we derive...

We consider a complete financial market with primitive assets and derivatives on these primitive assets. Nevertheless, the derivative assets are non-redundant in the market, in the sense that the market is complete, only with their existence. In such a framawork, we derive an equilibrium...

We define a coherent risk measures as set-valued maps satisfying some axioms. We show that this definition is a convenient extension of the real-valued risk measures introduced by Artzner, Delbaen, Eber and Heath (1998). We then discuss the aggregation issue, i.e. the passage from valued random...

In this paper we extend the theory of precautionary saving to the case in which uncertainty is multidimensional and we develop a matrix-measure of multivariate prudence. Furthermore, we characterize comparative prudence, decreasing and increasing prudence, the effect of uncertainty on the...