Repeated Games Played in a Network

Delayed perfect monitoring in an infinitely repeated discounted game is modelled by letting the players form a connected and undirected network. Players observe their immediate neighbors' behavior only, but communicate over time the repeated game's history truthfully throughout the network. The Folk Theorem extends to this setup, although for a range of discount factors strictly below 1, the set of sequential equilibria and the corresponding payoff set may be reduced. A general class of games is analyzed without imposing restrictions on the dimensionality of the payoff space. This and the bilateral communication structure allow for limited results under strategic communication only. As a by-product this model produces a network result; namely, the level of cooperation in this setup depends on the network's diameter, and not on its clustering coefficient as in other models.Repeated Game, Network, Delayed Perfect Monitoring, Communication

Repeated Games Played in a Network

Delayed perfect monitoring in an infinitely repeated discounted game is modelled by allocating the players to a connected and undirected network. Players observe their immediate neighbors’ behavior only, but communicate over time the repeated game’s history truthfully throughout the network. The Folk Theorem extends to this setup, although for a range of discount factors strictly below 1, the set of sequential equilibria and the corresponding payoff set may be reduced. A general class of games is analyzed without imposing restrictions on the dimensionality of the payoff space. Due to this and the bilateral communication structure, truthful communication arises endogenously only under additional conditions. The model also produces a network result; namely, the level of cooperation in this setup depends on the network’s diameter, and not on its clustering coefficient as in other models.Repeated Game, Delayed Perfect Monitoring, Network, Communication

Delayed Perfect Monitoring in Repeated Games

Delayed perfect monitoring in an in�nitely repeated discounted game is studied. A player perfectly observes any other player's action choice with a fixed, but finite delay. The observational delays between different pairs of players are heterogeneous and asymmetric. The Folk Theorem extends to this setup, although for a range of discount factors strictly below 1, the set of belief-free equilibria is reduced under certain conditions. This model applies to any situation in which there is a heterogeneous delay between information generation and the players-reaction to it.Repeated Game, Delayed Perfect Monitoring, Folk Theorem

Applications of Repeated Games in Wireless Networks: A Survey

A repeated game is an effective tool to model interactions and conflicts for players aiming to achieve their objectives in a long-term basis. Contrary to static noncooperative games that model an interaction among players in only one period, in repeated games, interactions of players repeat for multiple periods; and thus the players become aware of other players' past behaviors and their future benefits, and will adapt their behavior accordingly. In wireless networks, conflicts among wireless nodes can lead to selfish behaviors, resulting in poor network performances and detrimental individual payoffs. In this paper, we survey the applications of repeated games in different wireless networks. The main goal is to demonstrate the use of repeated games to encourage wireless nodes to cooperate, thereby improving network performances and avoiding network disruption due to selfish behaviors. Furthermore, various problems in wireless networks and variations of repeated game models together with the corresponding solutions are discussed in this survey. Finally, we outline some open issues and future research directions.Comment: 32 pages, 15 figures, 5 tables, 168 reference

The Repeated Prisoner’s Dilemma in a Network

Imperfect private monitoring in an infinitely repeated discounted Prisoner’s Dilemma played on a communication network is studied. Players observe their direct neighbors’ behavior only, but communicate strategically the repeated game’s history throughout the network. The delay in receiving this information requires the players to be more patient to sustain the same level of cooperation as in a complete network, although a Folk Theorem obtains when the players are patient enough. All equilibria under exogenously imposed truth-telling extend to strategic communication, and additional ones arise due to richer communication. There are equilibria in which a player lies. The flow of information is related with network centrality measures.Repeated Game, Prisoner’s Dilemma, Imperfect Private Monitoring, Network, Strategic Communication, Centrality

Repeated Commuting

We examine commuting in a game-theoretic setting with a continuum of commuters. Commuters' home and work locations can be heterogeneous. The exogenous transport network is arbitrary. Traffic speed is determined by link capacity and by local congestion at a time and place along a link, where local congestion at a time and place is endogenous. After formulating a static model, where consumers choose only routes to work, and a dynamic model, where they also choose departure times, we describe and examine existence of Nash equilibrium in both models and show that they differ, so the static model is not a steady state representation of the dynamic model. Then it is shown via the folk theorem that for sufficiently large discount factors the repeated dynamic model has as equilibrium any strategy that is achievable in the one shot game with choice of departure times, including the efficient ones. A similar result holds for the static model. Our results pose a challenge to congestion pricing. Finally, we examine evidence from St. Louis to determine what equilibrium strategies are actually played in the repeated commuting game.commuting; folk theorem

A Repeated Game Formulation of Energy-Efficient Decentralized Power Control

Decentralized multiple access channels where each transmitter wants to selfishly maximize his transmission energy-efficiency are considered. Transmitters are assumed to choose freely their power control policy and interact (through multiuser interference) several times. It is shown that the corresponding conflict of interest can have a predictable outcome, namely a finitely or discounted repeated game equilibrium. Remarkably, it is shown that this equilibrium is Pareto-efficient under reasonable sufficient conditions and the corresponding decentralized power control policies can be implemented under realistic information assumptions: only individual channel state information and a public signal are required to implement the equilibrium strategies. Explicit equilibrium conditions are derived in terms of minimum number of game stages or maximum discount factor. Both analytical and simulation results are provided to compare the performance of the proposed power control policies with those already existing and exploiting the same information assumptions namely, those derived for the one-shot and Stackelberg games.Comment: 25 pages, 5 figures, accepted for publication in IEEE Transaction on Wireless Communicatio

Self-enforcing Agreements on Water allocation

Many water allocation agreements in transboundary river basins are inherently unstable. Due to stochastic river flow, agreements may be broken in case of drought. The objective of this paper is to analyse whether water allocation agreements can be self-enforcing. An agreement is modelled as the outcome of bargaining game on river water allocation. Given this agreement, the bargaining game is followed by a repeated extensive-form game in which countries decide whether or not to comply with the agreement. I assess under what conditions such agreements are self-enforcing, given stochastic river flow. The results show that, for sufficiently low discounting, every efficient agreement can be sustained in subgame perfect equilibrium. Requiring renegotiation-proofness may shrink the set of possible agreements to a unique self-enforcing agreement. The solution induced by this particular agreement implements the “downstream incremental distribution”, an axiomatic solution to water allocation that assigns all gains from cooperation to downstream countries.Self-Enforcing Agreement, Repeated Extensive-Form Game, Water Allocation, Renegotiation-Proofness