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 provide a model of decision making under uncertainty in which the decision maker reacts to imprecision of the available data. Data is represented by a set of probability distributions. We axiomatize a decision criterion of the maxmin expected utility type, in which the revealed set of priors...

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...

Pensions reforms have been accelerating in Europe since the 1990s and the beginning of the 2000s : a common trend consists of strengthening the link between the individual contribution period and the level of pension. In a first part of the paper, we show that this common trend takes place...

I examine in detail the motives of bilateral aid allocation decisions, as they are revealed by data on bilateral aid commitments. I identify both self-interest and recipient needs and merits motives in aid allocation. Self-interest motives are related to economic and political ties between...

Most studies on the green tax reform issue point out that environmental taxes exacerbate pre-existing tax distortions, thereby increasing the welfare costs associated with the overall tax code. As a result, the optimal environmental tax should lie below the Pigovian level (or marginal social...

In this paper, we study the on-line version of the bin-packing problem. We analyze the approximation behaviour of an on-line bin-packing algorithm under an approximation criterion called differential ratio. We are interested in two types of results : the differential competitivity ratio...

The aim of this paper is to scope the different institutional possibilities offered to the Europeans infrastructure managers into obtaining the most efficient cooperation between them and evaluate the possible effects of the European commission policy on this topic. The goal of this cooperation...

This paper investigates the relative importance of different types of news in driving significant stock price changes of firms in the defense industry. We implement a systematic event study with a sample of the 58 largest publicly listed companies in the defense industry, over the time period...

We introduce a two-period general equilibrium model with uncertainty and incomplete financial markets, where default is allowed and agents face in case they do default an utility penalty, which is their own private information. In this setting, if agents have heterogeneous characteristics they...