Coalition Structures in Weighted Voting Games

Abstract. Weighted voting games are a popular model of collaboration in multiagent systems. In such games, each agent has a weight (intuitively corresponding to resources he can contribute), and a coalition of agents wins if its total weight meets or exceeds a given threshold. Even though coalitional stability in such games is important, existing research has nonetheless only considered the stability of the grand coalition. In this paper, we introduce a model for weighted voting games with coalition structures. This is a natural extension in the context of multiagent systems, as several groups of agents may be simultaneously at work, each serving a different task. We then proceed to study stability in this context. First, we define the CS-core, a notion of the core for such settings, discuss its non-emptiness, and relate it to the traditional notion of the core in weighted voting games. We then investigate its computational properties. We show that, in contrast with the traditional set...

• Type: Conference
• Year: 2008
• Where: ECAI
• Authors: Edith Elkind, Georgios Chalkiadakis, Nicholas R. Jennings
• Keywords: Artificial Intelligence, ECAI 2008, Multiagent Systems, Total Weight Meets, Weighted Voting Games