In physical models it is well understood that the aggregate behaviour of a system is not in one to one correspondence with the behaviour of the average individual element of that system. Yet, in many economic models the behaviour of aggregates is thought of as corresponding to that of an...

In France today we are faced with three problems in training young economists. Firstly we have a system in which every university is supposed to offer equivalent degrees and this means that more than half of the students disappear without getting a degree. We cannot offer the sort of courses...

This paper discusses modern macroeconomic and financial models in the light of the current crisis. Theory has been revealed to be inadequate in its explanation of the origins and the nature of the crisis, as Jean-Claude Trichet the Governor of the European Central bank and his colleagues at...

This work introduces a special issue of the Journal of Economic Behavior and Organization on the emergence and impact of market institutions in wholesale fish markets. The analysis of fish markets has a respectable pedigree also in terms of the description of how they function. A major advantage...

This paper examines the process by which agents learn to act in economic environments. Learning is particularly complicated in such situations since the environment is, at least in part, made up of other agents who are also learning. At best, one can hope to obtain analytical results for a...

Ce papier, préparé pour un symposium en l'honneur de Marc Barbut, discute des thèmes qui ont lié ses intérêts intellectuels et ceux de son laboratoire le CAMS aux thèmes de l'économie. En particulier il s'agit de l'historique de la notion de marchés efficaces et le refus systématique...

What I argue in this paper is that the direction economics ,and particularly theoretical economics, took in the 20th century was to a great extent due to Walras' influence. This was not so much the result of his own results but rather a reflection of his vision. He was convinced that economics...

This short paper argues that rationally motivated coordination between agents is an important ingredient to understand the current economic crisis. We argue that changes in parameters that model the structure of a macro-economy or financial markets are not exogenous but arise as agents adopt...

Nous comparons à l'aide d'un modèle multi-agents deux types d'organisations fréquemment rencontrées dans les marchés de biens périssables: les enchères simultanées descendantes ou enchères hollandaises, et la négociation de gré à gré sans prix affichés ; Notre approche consiste à...

We analyse the interaction between a seller and customers in a shop on the fruits and vegetables wholesale market in Marseille using an unique data set. We find that customers' bargaining activity is correlated with the kind and location of the business. To determine how the interactions between...