Forming effective coalitions is a major research challenge in AI and multi-agent systems. A Coalition Structure Generation (CSG) problem involves partitioning a set of agents into coalitions so that the social surplus is maximized. Ohta et al. introduce an innovative direction for solving CSG, i.e., by representing a characteristic function as a set of rules, a CSG problem can be formalized as ...

Sen’s libertarian paradox is ascribed to the inevitable conflict between the Pareto criterion and individuals’ rights to create negative externalities. Finite coalitions can effect exchanges of rights through Coaseian bargains in order to resolve inefficiencies due to local externalities. With a continuum of agents, however, finite coalitions are powerless to affect widespread externalities, ex...

We introduce a new formal approach to social networks in order to distinguish four ways in which coalitions change. First, the agents in the network change. Second, dependencies among the agents change, for example due to addition or removal of powers and goals of the agents. Third, norms can introduce normative dependencies for obligations and prohibitions. Fourth, coalitions can change due to...

This paper investigates algorithmic computability of simple games (voting games). It shows that (i) games with a finite carrier are computable, (ii) computable games have both finite winning coalitions and cofinite losing coalitions, and (iii) computable games violate any conceivable notion of anonymity, including finite anonymity and measurebased anonymity. The paper argues that computable gam...

We analyze the formation of partnerships as a sequential game with moral hazard within coalitions; once formed, partnerships compete a la Cournot in the marketplace. When moral hazard within coalitions is very severe, no partnership will form. However, we show that when moral hazard is not too severe the coalition structure will be either similar to or more concentrated than it is without moral...