In this paper we deal with the basic two-period consumption saving problem where the first and second period consumption utility, v and u is assumed to be concave re- spectively as usually. We prove that for the rank dependent utility model, prudence is fully characterized by the convexity of u/...

In this paper, we examine the eect of a decrease in risk on the demand for risky asset in the standard portfolio problem. We introduce a new class of dominance, that we name relative order and we prove that this class of dominance is consistent both with central dominance introduced by Gollier...

The concept of a non-extreme-outcome-additive capacity (neo-additive capacity ) is introduced. Neo-additive capacities model optimistic and pessimistic attitudes towards uncertainty as observed in many experimental studies. Moreover, neo-additive capacities can be applied easily in economic...

In markets where dealers play a central role, bid-ask spreads inhibit asset valuation as defined by the formation cost of a replicating portfolio. We introduce a nonlinear valuation formula similar to the usual expectation with respect to the risk-adjusted probability measure. This formula...

This paper explores the consequences of non-additive expected utility on risk-sharing and equilibrium in a general equilibrium set-up. We establish that convexity of an agent's preferences (or strong uncertainty aversion) is equivalent to the convexity of his capacity and concavity of his...

We show, in the Choquet expected utility model, that prefernece for diversification, that is, convex prefrences, is equivalent to a concave utility index and a convex capacity. We then introduce a weaker notion of diversification, namely "sure diversification". We show that this implies that the...

A usual argument in finance refers to no arbitrage opportunities for the positivity of the bid-ask spread. Here we follow the decision theory approach and show that if positivity of the bid-ask spread is identified with strong risk aversion for an expended utility market-marker, this is no...

Cumulative prospect theory was introduced by Tversky and Kahneman to combine the empirical realism of their original prospect theory with the theoretical advantages of rank-dependent utility. Preference axiomatizations were provided in several papers. All exosting axiomatizations, however, only...

In a previous paper, Abouda and Chateauneuf proved that for RDEU maximizing MM with non-increasing marginal utility, positivity of the bid-ask spread can be identified with a very weak form of risk aversion SMRA. We perform here a more thorough study of SMRA, firstly in a general setting, and...