International Game Theory Review

We consider an infinite horizon bargaining game in which a deadline can arise with positive probability and where players possess an endogenous commitment device. We show that for any truncation of the game, the equilibrium agreement can only take place if the deadline arises within this finite horizon. Since the deadline is an uncertain event, the equilibrium exhibits agreements which are delayed with positive probability.

In this paper, we consider a pure exchange economy with a finite number of agents who behave strategically on endowments. A notion of strategic equilibrium with partial disposability is defined and it is shown the existence of mixed strategies equilibria. Purification results on the strategic equilibrium are obtained by considering a Walrasian endowment game with incomplete information. Finally, we obtain an asymptotic result by replicating the economy.

Weiss (1981) established core equivalence and the existence of competitive equilibria in finitely additive exchange economies. To underline the relevance of finitely additive economies we present in this note an example with a close connection to finite exchange economies.

This paper analyses whether the effect of compensation of former spouses after divorce has an impact on the probability of divorces occurring. In particular, it is assumed that the income difference after divorce is shared equally between former spouses, in line with rules in Germany. The reference situation within the marriage is, on the one hand, Nash-bargaining and, on the other, Becker-type altruistic sharing. It turns out that sharing increases the probability of divorce where there are no changes in labor supply. If labor supply is adjusted to the sharing rules after divorce, no general result is possible. If productivity is similar, the sharing rule will lead to less divorces than in the absence of such a regulation. However with large productivity differences separations are more probable in the case of income sharing compared to a situation without such a compensation. Labor supply adjustment in general reduces the number of divorces compared to the situation without labor supply adjustment.

We consider a two-person multi-stage game with a very sparse information structure. Two players in the blind alternately move a chip which toggles the colors of nodes located around a circle. The second player also controls and picks the stopping time which is unknown to the first player. We solve this game by showing the first player has a strategy which is uniformly optimal against the strategies of the second player.

A buyout option enhances an auction by allowing a bidder to purchase the item at a pre-specified price (instead of attempting to obtain the item by way of auction). A comparison is made between the ex ante welfare of bidders in an auction with a buyout option to a traditional auction with no such option. The impact on bidder welfare is shown to depend upon the distribution from which bidder valuations are drawn. In comparison to a traditional auction with no buyout option, when a buyout option is in place either: all bidders are weakly better off (in which case the option results in an ex ante Pareto improvement) or bidders with "relatively high valuations" are worse off.

In this paper we give an overview of various methods used to study cooperation within a set of players. Besides the classical games with transferable utility and games without transferable utility, recently new models have been proposed: the coalition formation games. In these, each player has his own preferences over coalitions to which he could belong and the quality of a coalition structure is evaluated according to its stability. We review various definitions of stability and restrictions of preferences ensuring the existence of a partition stable with respect to a particular stability definition. Further, we stress the importance of preferences over sets of players derived from preferences over individuals and review the known algorithmic results for special types of preferences derived from the best and/or the worst player of a coalition.

This paper deals with the non-emptiness of the stability set for any proper voting game. We present an upper bound on the number of alternatives which guarantees the non emptiness of this solution concept. We show that this bound is greater than or equal to the one given by Le Breton and Salles (1990) for quota games.

This article introduces a model of rationality that combines procedural utility over actions with consequential utility over payoffs. It applies the model to the Prisoners' Dilemma and shows that empirically observed cooperative behaviors can be rationally explained by a procedural utility for cooperation. The model characterizes the situations in which cooperation emerges as a Nash equilibrium. When rational individuals are not solely concerned by the consequences of their behavior but also care for the process by which these consequences are obtained, there is no one single rational solution to a Prisoners' Dilemma. Rational behavior depends on the payoffs at stake and on the procedural utility of individuals. In this manner, this model of procedural utility reflects how ethical considerations, social norms or emotions can transform a game of consequences.

Moulin (1984) describes the class of nice games for which the solution concept of point-rationalizability coincides with iterated elimination of strictly dominated strategies. As a consequence nice games have the desirable property that all rationalizability concepts determine the same strategic solution. However, nice games are characterized by rather strong assumptions. For example, only single-valued best responses are admitted and the individual strategy sets have to be convex and compact subsets of the real line ℝ. This note shows that equivalence of all rationalizability concepts can be extended to multi-valued best response correspondences. The surprising finding is that equivalence does not hold for individual strategy sets that are compact and convex subsets of ℝⁿ with n ≥ 2.

This paper considers an agency contracting with multiple tasks. The agent is privately informed on some tasks, but he must gather information on the other. We show that depending on the cost to gather information, task assignment is employed as an instrument to induce information gathering, or as an instrument to induce a truthful report.

In this paper we characterize a general existence theorem concerning E-points for n-persons extensive games with complete information. We provide a sufficient and necessary condition for the existence of such E-points.

In the case of natural duopoly, we suggest a finitely repeated game between two incumbent firms and a potential entrant that limits the incumbent firms' power and compels them to approach economic efficiency. We prove that such a game admits a perfect subgame equilibrium along which the incumbent firms maintain with equal quantities while preventing entry. Moreover, the incumbents' strategies along this path converge to average cost pricing quantities as the number of periods goes to infinity.

A dynamic normal formulation for differential games is introduced and the "pedestrian principle" is discussed as a means of dynamically implementing the equilibrium strategy in a single game. Our formulation emphasizes the distinction between a player's rational prediction and the actual evolution of the game dynamics. To model the free will of players, a randomized strategy is introduced which serves as the justification of mixed strategies and the bridge from a static analysis to a dynamic one. Existence of Nash equilibrium in the class of mixed strategies is proved for non-cooperative deterministic differential games.

Under dynamic cooperation a player may use 'irrational' acts to extort additional gains if later circumstances allow. In this article we present a condition under which even if irrational behaviors appear later in the game the concerned player would still be performing better under the cooperative scheme.