Negotiating the membership

In cooperative games in which the players are partitioned into groups, we study the incentives of the members of a group to leave it and become singletons. In this context, we model a non-cooperative mechanism in which each player has to decide whether to stay in his group or to exit and act as a singleton. We show that players, acting myopically, always reach a Nash equilibrium.Cooperative game, coalition structure, Owen value, Nash equilibrium

Implementation of the levels structure value

We implement the levels structure value (Winter, 1989) for cooperative transfer utility games with a levels structure. The mechanism is a generalization of the bidding mechanism by Perez-Castrillo and Wettstein (2001).levels structure value implementation TU games

Bargaining with commitments

We study a simple bargaining mechanism in which each player puts a prize to his resources before leaving the game. The only expected final equilibrium payoff can be defined by means of selective marginal contributions vectors, and it coincides with the Shapley value for convex games. Moreover, for 3-player games the selective marginal contributions vectors determine the core when it is nonempty.demand commitment game bargaining

The Harsanyi paradox and the 'right to talk' in bargaining among coalitions

We introduce a non-cooperative model of bargaining when players are divided into coalitions. The model is a modification of the mechanism in Vidal-Puga (Economic Theory, 2005) so that all the players have the same chances to make proposals. This means that players maintain their own 'right to talk' when joining a coalition. We apply this model to an intriguing example presented by Krasa, Tamimi and Yannelis (Journal of Mathematical Economics, 2003) and show that the Harsanyi paradox (forming a coalition may be disadvantageous) disappears.cooperative games bargaining coalition structure Harsanyi paradox

A bargaining approach to the consistent value for NTU games with coalition structure

The mechanism by Hart and Mas-Colell (1996) for NTU games is generalized so that a coalition structure among players is taken into account. The new mechanism yields the Owen value for TU games with coalition structure as well as the consistent value (Maschler and Owen 1989, 1992) for NTU games with trivial coalition structure. Furthermore, we obtain a solution for pure bargaining problems with coalition structure which generalizes the Nash (1950) bargaining solution.NTU consistent bargaining stationary subgame perfect equilibrium

Forming societies and the Shapley NTU value

We design a simple protocol of coalition formation. A society grows up by sequentially incorporating new members. The negotiations are always bilateral. We study this protocol in the context of non-transferable utility (NTU) games in characteristic function form. When the corresponding NTU game (N,V) satisfies that V(N) is flat, the only payoff which arises in equilibrium is the Shapley NTU value.Shapley NTU value, sequential formation of coalitions, subgame perfect equilibrium

A fair rule in minimum cost spanning tree problems

We study minimum cost spanning tree problems and define a cost sharing rule that satisfies many more properties than other rules in the literature. Furthermore, we provide an axiomatic characterization based on monotonicity properties.minimum cost spanning tree, cost sharing

On the Shapley value of a minimum cost spanning tree problem

We associate an optimistic coalitional game with each minimum cost spanning tree problem. We define the worth of a coalition as the cost of connection assuming that the rest of the agents are already connected. We define a cost sharing rule as the Shapley value of this optimistic game. We prove that this rule coincides with a rule present in the literature under different names. We also introduce a new characterization using a property of equal contributions.minimum cost spanning tree problems Shapley value

The NTU consistent coalitional value

We introduce a new value for NTU games with coalition structure. This value coincides with the consistent value for trivial coalition structures, and with the Owen value for TU games with coalition structure. Furthermore, we present two characterizations: the first one using a consistency property and the second one using balanced contributions properties.consistent coalition structure value NTU balanced contributions

The folk solution and Boruvka's algorithm in minimum cost spanning tree problems

The Boruvka's algorithm, which computes the minimum cost spanning tree, is used to define a rule to share the cost among the nodes (agents). We show that this rule coincides with the folk solution, a very well-known rule of this literature.minimum cost spanning tree; Boruvka's algorithm; folk solution