Uniqueness of Coalitional Equilibria

Coalitional Nash Equilibria

Let G be an N -player game in strategic form and C be a set of permissible coalition of players (exogenously given). A strategy profile σ is a coalitional-equilibrium if no permissible coalition in C has a unilateral deviation that profits to all its members. At the two extremes: when C contains only singleton players, σ reduces to a Nash equilibrium and when C consists on all coalitions of pla...

Coalitional Bargaining Equilibria

This paper takes up the foundational issue of existence of stationary subgame perfect equilibria in a general class of coalitional bargaining games that includes many known bargaining models and models of coalition formation. General sufficient conditions for existence of equilibria are currently lacking in many interesting environments: bargaining models with non-concave stage utility function...

Correlated equilibria, incomplete information and coalitional deviations

This paper proposes new concepts of strong and coalition-proof correlated equilibria where agents form coalitions at the interim stage and share information about their recommendations in a credible way. When players deviate at the interim stage, coalition-proof correlated equilibria may fail to exist for two-player games. However, coalitionproof correlated equilibria always exist in dominance-...

Uniqueness of stationary equilibrium payoffs in coalitional bargaining

We study a model of sequential bargaining in which, in each period before an agreement is reached, a proposer is randomly selected, the proposer suggests a division of a pie of size one, each other agent either approves or rejects the proposal, and the proposal is implemented if the set of approving agents is a winning coalition for the proposer. We show that stationary equilibrium outcomes of ...

Existence of Sunspot Equilibria and Uniqueness of Spot Market Equilibria: The Case of Intrinsically Complete Markets