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...

In an exchange economy with no aggregate uncertainty, and Bayesian agents, Pareto optimal allocations provide full insurance if and only if the agents have a common prior. It is hard to explain why there is relatively so little betting taking place. One is led to ask, when are full insurance...

We study attitudes towards risk in the Rank Dependent Expected Utility (RDEU) model. This model replaces expected utility by another functional, which is characterised by two functions, a utility function on outcomes in conjunction with a probability-perception function. We use the notion of...

Normative models of behaviour under risk in the framework of expected utility (EU) or under uncertainty in the framework of subjective expected utility (SEU) are very limited. In this survey paper, it is shown that non-expected utility (non-EU) models based on the Choquet integral allow for much...