A pure hedonic game describes the situation where player's utility depends only on the identity of the members of the group he belongs to. The paper provides a necessary and sufficient condition for the existence of core-partition in hedonic games. The condition is based on a new concept of balancedness, called pivotal balancedness. Pivotal balancedness involves especially the notion pivotal distribution that associates to each coalition a subgroup of players in the coalition. Then, we proceed to a review of several sufficient conditions for core-partition existence showing how the results can be unified through suitably chosen pivotal distributions.

International audienceWe prove the non-emptiness of the core of an NTU game satisfying a condition of payoff-dependent balancedness, based on transfer rate mappings.We also define a new equilibrium condition on transfer rates and we prove the existence of core payoff vectors satisfying this condition. The additional requirement of transfer rate equilibrium refines the core concept and allows the selection of specific core payoff vectors. Lastly, the class of parameterized cooperative games is introduced. This new setting and its associated equilibrium-core solution extend the usual cooperative game framework and core solution to situations depending on an exogenous environment. A non-emptiness result for the equilibrium-core is also provided in the context of a parameterized cooperative game. Our proofs borrow mathematical tools and geometric constructions from general equilibrium theory with non-convexities. Applications to extant results taken from game theory and economic theory are given

a b s t r a c tWe identify a natural counterpart of the standard GARP for demand data in which goods are all indivisible. We show that the new axiom (DARP, for ''discrete axiom of revealed preference'') is necessary and sufficient for the rationalization of the data by a well-behaved utility function. Our results complement the main finding of Polisson and Quah (2013), who rather minimally modify the original consumer problem with indivisible goods so that the standard GARP still applies.

Le recrutement des jeunes enseignants chercheurs en France se fait de manière centralisée Le ministère calcule les affectations en fonction des listes de classements soumis par les comités de sélection et des listes de voeux soumis par les candidats. Les enjeux stratégiques du recrutement en France sont souvent mal compris, ou du moins peu connus. Nous montrons que la procédure d'affectation, tout en restant opaque pour les candidats, satisfait des propriétés souhaitables de stabilité et d'optimalité qui favorisent les candidats. Pour ce faire, nous identifions la règle d'affectation utilisée par le ministèreà partir des informations misesà disposition des candidats. La structure de l'algorithme qui permet de produire ces affectations estégalement analysée. Enfin, nous discutons de l'existence des quotas sur le nombre des candidats classés et des ultimes changements apportés au concours de Maîtres de Conférences ainsi que de leurs relations avec des comportements localistes.