Equilibrium Selection via Communication Partition

Coordinating the behaviour of self-interested agents in the presence of multiple Nash equilibria is a major research challenge for multiagent systems. Pre-game communication between all the players can aid coordination in cases where the Pareto-optimal payoff is unique, but can lead to deadlocks when there are multiple payoffs on the Pareto frontier. We consider a communication partition where only players within the same coalition can communicate with each other. We show that under some natural assumptions about symmetry and the conditions under which players within the same coalition can reach an agreement about their joint actions, certain communication partitions can induce socially optimal outcomes in singleton congestion games. This game is a reasonable model for a decentralised, anonymous system where players are required to choose from a range of identical resources, and incur costs that are increasing and convex in the total number of players sharing the same resource. The communication partition can be seen as a mechanism for inducing efficient outcomes in this context.