Stability of coalitions in a heterogeneous population

The paper considers a model of coalition formation by players with different preferences characterized by ideal points. The coalition policy is determined as a median of its members ideal points distribution. The payoff of an agent depends on the size and the policy of the coalition he joins. A new feature of the model is that the set of players is also heterogeneous in a parameter of the payoff function: we assume that some amount of a new type of agents with a different evaluation of the distance between their ideal points and the coalition policy is added to the original type. The both types are randomly distributed in the set of ideal points. We study existence and properties of Nash and coalitional equilibria for this model.