Games and Economic Behavior最新文献

In this paper, we introduce a two-stage Bayesian persuasion model in which a third-party platform controls the information available to the sender about users' preferences. We aim to characterize the optimal information disclosure policy of the platform, which maximizes average user utility, under the assumption that the sender also follows its own optimal policy. We show that this problem can be reduced to a model of market segmentation, in which probabilities are mapped into valuations. We then introduce a repeated variation of the persuasion platform problem in which myopic users arrive sequentially. In this setting, the platform controls the sender's information about users and maintains a reputation for the sender, punishing it if it fails to act truthfully on a certain subset of signals. We provide a characterization of the optimal platform policy in the reputation-based setting, which is then used to simplify the optimization problem of the platform.

Social dilemmas often impose negative externalities on third parties. We experimentally analyze gender differences in cooperation in such a setting, i.e., a prisoner's dilemma game, with a passive third party that may be harmed when active players mutually cooperate. Applying a within-subjects setting, we compare cooperation under anonymity and social information, as personal characteristics are commonly known in real-life relations. Results show that the presence of a negative externality particularly affects guilt-averse women, who cooperate less often independently of the degree of information they receive. No gender difference is found absent negative externalities.

The Shapley value equals a player's contribution to the potential of a game. The potential is a most natural one-number summary of a game, which can be computed as the expected accumulated worth of a random partition of the players. This computation integrates the coalition formation of all players and readily extends to games with externalities. We investigate those potential functions for games with externalities that can be computed this way. It turns out that the potential that corresponds to the MPW solution introduced by Macho-Stadler et al. (2007, J. Econ. Theory 135, 339–356) is unique in the following sense. It is obtained as the expected accumulated worth of a random partition, it generalizes the potential for games without externalities, and it induces a solution that satisfies the null player property even in the presence of externalities.

A recurring theme in the study of society is the concentration of influence and power that is driven through unequal membership of groups and associations. In some instances, these bodies constitute a small world while in others they are fragmented into distinct cliques. This paper presents a new model of clubs and networks to understand the sources of individual marginalization and the origins of small and large worlds.

This study addresses the emergence of (unarmed) peace and investments in arms within a guns-vs-butter conflict setting. We introduce a novel feature within the conflict game and separate the decision to start a conflict and the investment in arms, following the theoretical framework of Garfinkel and Syropoulos (2021). Based on this model we experimentally examine the emergence of peace while varying resource inequality among conflicting parties. We find that inequality leads to more conflicts and higher investments in arms. Despite these trends, achieving a state of unarmed peace is rarely observed in both treatments. Our results highlight the critical role of trust in attaining peaceful outcomes and show that armed peace, although not an optimal strategy in either treatment, is one of the most frequently chosen decisions.

In a variety of economic situations discrete agents choose one resource among several available resources and, once admitted to the resource of choice, divide it among fellow agents admitted there. The amount of the resource an agent gets is proportional to her relative ability to acquire this particular resource, what we refer to as an agent's weight at the resource. The relevant applications include students self-selecting into colleges, politicians self-selecting into races, and athletes self-selecting into teams. We find that this game has a pure-strategy Nash equilibrium in at least three special cases: 1) when agents have the same weight at each resource, 2) when all resources are the same, 3) when there are only two resources. We also show that this game always has an approximate Nash equilibrium when the number of players is large. Existence in the general case remains an open problem.

We consider first-price auctions with independent and private valuations that have asymmetric valuation distributions and supports. We first show the existence of equilibrium in these auctions through a perturbation approach, thereby establishing that the limit of Bayesian Nash equilibria (BNE) of such perturbed auctions is indeed the Bayesian Nash equilibrium (BNE) of the limit auction with asymmetric supports. We then characterize this BNE and show that the ε-equilibrium (ε-BNE) of the auction with asymmetric supports is a BNE of “close” auctions with common supports. We then demonstrate some numerical examples.

In our information cascade experiments, we study social learning in decision-making situations in which decisions “not to do” are unobservable. Subjects, in sequence, choose whether to invest or not, without knowing their position. They observe a private signal and the number of investments made by their predecessors, but not how many predecessors have chosen not to invest. We find that down cascades, in which agents neglect the signal and do not invest, occur, in contrast with the equilibrium predictions. Up cascades, in which agents invest independently of the signal, occur, but less than in equilibrium.

We report experimental findings on the role of charitable promises in settings with posted offers. We vary the enforceability of such promises within variants of ultimatum games where the proposer suggests a split between herself, the responder and a charitable donation. By reneging on initial pledges, dishonest proposers can change the final allocation to their advantage. Providing ex post information on actual donations while leaving the contract incomplete outperforms a complete contract where proposers cannot renege on their charitable promises. The ex post information allows proposers to improve their image by voluntarily giving more than pledged and thus proving that the charitable pledge was not used for strategic reasons. We identify proposer competition as another (surprising) mechanism that partly eliminates cheating among accepted offers, but it also favors offers without charitable pledge.