This paper discusses models of choice under imprecise objective proba- bilistic information featuring beliefs about beliefs - second order beliefs. A new model, called Second Order Dual Expected Utility (SODEU) featuring non-additive second order beliefs is introduced, axiomatized and systemati-...

We axiomatize a model of decision under objective ambiguity or imprecise risk. The decision maker forms a subjective (non necessarily additive) belief aboutthe likelihood of probability distributions and computes the average expected utility of a given act with respect to this second order...

The final step in the proof of Proposition 1 (p.311) of Mukerji and Tallon (2003) may not hold in generalbecause $\varepsilon0$ in the proof cannot be chosen independently of $w,z$. We point out by a counterexample that the axioms they impose are too weak for Proposition 1. We introduce a...

This chapiter of a collective book is dedicated to classical decision models under uncertainty, i.e. under situations where events do not have "objective" probabilities with which the Decision Marker agrees. We present successively the two main theories, their axiomatic, the interpretation and...

It is widely thought that incomes risks can be shared by trading infinancial assets. But financial assets typically carry some riskidiosyncratic to them, hence, disposing incomes risk using financial assetswill involve buying into the inherent idiosyncratic risk. However, standardtheory argues...

This paper analyzes optimal wage contracting assuming agents are not subjective expectedutility maximizers but are, instead, ambiguity (or uncertainty) averse decision makers whomaximize Choquet expected utility. We show that such agents will choose not to include anyindexation coverage in their...

In this article, we focus on two types of "aversion" which we deem essential aspects of the notion of trust: betrayal aversion (social) and ambiguity aversion (a special case of aversion to uncertainty). Based on trust-games studies in experimental economics and neuroeconomics, our main goal is...

In this paper, ambiguity aversion to uncertain survival probabilities is introduced in a life-cycle model with a bequest motive to study the optimal demand for annuities. Provided that annuities return is sufficiently large, and notably when it is fair, positive annuitization is known to be...

We consider a family of exchange economies where consumers have multiprior preferences representing their ambiguity aversion. Under a linear independence assumption, we prove that regular economies are generic. Regular economies exhibit enjoyable properties: odd finite number of equilibrium...

We review recent advances in the field of decision making under uncertainty or ambiguity.