Tribute to Jean-Yves Jaffray by the French Group of Decision Theory

This paper presents an axiomatic model of decision making which incorporates objective but imprecise information. We axiomatize a decision criterion of the multiple priors (or maxmin expected utility) type. The model achieves two primary objectives. First, it explains how subjective belief...

We develop an axiomatic approach to decision under uncertainty that explicitly takes into account the information available to the decision maker. The information is described by a set of priors and a reference prior. We define a notion of imprecision for this informational setting and show that...

We provide a general theorem on the aggregation of preferences under uncertainty. We study, in the Anscombe-Aumann setting a wide class of preferences, that includes most known models of decision under uncertainty (and state-dependent versions of these models). We prove that aggregation is...

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...

We axiomatize in the Anscombe–Aumann setting a wide class of preferences called rank-dependent additive preferences that includes most known models of decision under uncertainty as well as state dependent versions of these models. We prove that aggregation is possible and necessarily linear if...

Ever since its introduction by Foley [1967] and Varian [1974], the notion of fairness has been one of the most extensively used notion to evaluate allocations on an ethical basis. Whereas there is an extensive literature on the efficiency properties of allocations in economies with uncertainty...

We show that when decision makers are of the multiple prior kind, there is an equivalence between no betting and non empty intersection of the sets of priors.

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...

Nous proposons dans cet article un panorama des modélisations de la prise de décision dans des situations de risque ou d'incertain. Une attention particulière est portée aux incertitudes environnementales. Après avoir rappelé les modèles canoniques d'espérance d'utilité, nous...