A conflict-free arbitration scheme in a large population

This paper studies allocations that can be implemented by an arbitrator subject to the constraint that the agents' outside option is to start bargaining by themselves. As the population becomes large, the set of implementable allocations shrinks to a singleton point - the conflict-free allocation. Finally, the conflict-free allocation can be implemented via a simple "lobbying" game where parties composed of agents with similar preferences bid for the right to be the first proposer in a bargaining game among the parties, i.e. in the "political game".non-cooperative bargaining, arbitration, implementation

On the Existence of Markov Perfect Equilibria in Perfect Information Games

We study the existence of pure strategy Markov perfect equilibria in two-person perfect information games. There is a state space X and each period player's possible actions are a subset of X. This set of feasible actions depends on the current state, which is determined by the choice of the other player in the previous period. We assume that X is a compact Hausdorff space and that the action correspondence has an acyclic and asymmetric graph. For some states there may be no feasible actions and then the game ends. Payoffs are either discounted sums of utilities of the states visited, or the utility of the state where the game ends. We give sufficient conditions for the existence of equilibrium e.g. in case when either feasible action sets are finite or when players' payoffs are continuously dependent on each other. The latter class of games includes zero-sum games and pure coordination games.dynamic games, Markov perfect equilibrium

Dynamic stable set

We study a dynamic vNM stable set in a compact metric space under the assumption of complete and continuous dominance relation. Internal and external stability are defined with respect to farsighted dominance. Stability of an outcome is conditioned on the history via which it is reached. A dynamic stable set always exists. Any covering set by Dutta (1988) coincides with the set of outcomes that are implementable via a dynamic stable set. The maximal implementable outcome set is a version of the ultimate uncovered set.vNM stable set, dynamic, history

Auction Design without Commitment

We study auction design when parties cannot commit themselves to the mechanism. The seller may change the rules of the game and the buyers choose their outside option at all stages. We assume that the seller has a leading role in equilibrium selection at any stage of the game. Stationary equilibria are characterized in the language of vonNeumann-Morgenstern stable sets. This simplifies the analysis remarkably. In the one buyer case, we obtain the Coase conjecture: the buyer obtains all the surplus and efficiency is reached. However, in the multiple buyer case the seller can achieve more: she is able to commit to the English auction. Typically the converse also holds, the English auction is the only stable auction mechanism.Auction theory, commitment, stable sets

On the Existence of Undominated Elements of Acyclic Relations

We study the existence of undominated elements of acyclic and irreflexive relations. A sufficient condition for the existence is given in the general case without any topological assumptions. Sufficient conditions are also given when the relation in question is defined on a compact Hausdorff space. We study the existence of fixed points of acyclic correspondences, the existence of stable sets, and the possibility of representing the relation by a real valued function.acyclic relations, undominated elements

Auction Design without Commitment

We study auction design when parties cannot commit to the mechanism. The seller may change the rules of the game any number of times and the buyers may choose their outside option at any stage of the game. A dynamic consistency condition and an optimality condition property are defined to characterize the seller's mechanism selection behavior. The unique stationary mechanism selection rule that meets the conditions is the English auction.auctions, commitment, consistency, one-deviation property, stationarity

Valuating Payoff Streams under Unequal Discount Factors

We study repeated prize allocation problem when the discount factors f the agents are not equal. It is shown that the feasible set of payoffs is not well behaved. In particular, it is not convex as it contains holes and caves. The Pareto frontier is everywhere discontinuous and there is an open subset of discount factors such that the feasible set is totally disconnected.payoffs, differentiated discount factor, repeated games

One-deviation principle in coalition formation

We study coalitional one-deviation principle in a framework a la Chwe (1994). The principle requires that an active coalition or any of its subcoalition will not benefit from a single deviation to a strategy that specifies, for each history of coalitional moves, an active coalition and its move. A strategy meeting the one-deviation property is characterized. Moreover, it is shown to exist. Finally, the results are compared to the existing theories of coalitional games.one-deviation principle, coalition formation

Bargaining with Many Players: A Limit Result

We provide a simple characterization of the stationary subgame perfect equilibrium of an alternating offers bargaining game when the number of players increases without a limit. Core convergence literature is emulated by increasing the number of players by replication. The limit allocation is interpreted in terms of Walrasian market for being the first proposer.non-cooperative bargaining, stationary equilibrium, replication, Walrasian market

Multilateral Non-Cooperative Bargaining in a General Utility Space

We consider an n-player bargaining problem where the utility possibility set is compact, convex, and stricly comprehensive. We show that a stationary subgame perfect Nash equilibrium exists, and that, if the Pareto surface is differentiable, all such equilibria converge to the Nash bargaining solution as the length of a time period between offers goes to zero. Without the differentiability assumption, convergence need not hold.multilateral, bargaining, general utility set