Stable Hedonic Cooperation Structures∗

We consider a model in which players can form links between themselves under mutual agreement, and the set of all pairwise agreements is called a cooperation structure. We stress that we are particularly interested to the case when some players are antagonistic, i.e., that they are separately “desirable” for someone, but “undesirable” when they are together. We define a class of preferences that ensures the stability of cooperation structures, if each player is sensitive to her direct neighbors only. However, it turns out that if players are sensitive to their indirect neighbors, antagonism between player may easily forbid the existence of stable cooperation structures, for a large class of preference profile.