This chapter surveys a sizable and growing literature on coalition formation. We refer to theories in which one or more groups of agents (“coalitionsâ€) deliberately get together to jointly determine within-group actions, while interacting noncooperatively across groups. The chapter...

A minimal requirement on allocative efficiency in the social sciences is Pareto optimality. In this paper, we identify a close structural connection between Pareto optimality and perfection that has various algorithmic consequences for coalition formation. Based on this insight, we formulate the...

We address the issue of bidder ring formation in single and multi-unit Vickrey auctions. We address this issue in a bargaining game set up under the assumption that valuation of bidders is commonly known only amongst themselves. In the single unit case, we show that the equilibrium coalition...

We provide a new proof of the non-emptiness of approximate cores of games with many players of a finite number of types. Earlier papers in the literature proceed by showing that, for games with many players, equal-treatment cores of their "balanced cover games", which are non-empty, can be...

This paper analyzes the recent mergers in the oil industry. Oil is assumed to be a homogeneous good which is produced by a small number of firms with different unit costs. Merger formation is endogenously explained as a result of cooperative decisions. We show that the mergers are amongst very...

This paper analyzes endogenous merger formation in oligopolistic markets where firms have different unit production costs. We reformulate the merger model, introduced by Barros (1998), by employing the core as cooperative equilibrium concept. We show that, depending on the size asymmetry in the...

In this paper we study hedonic games where each player views every other player either as a friend or as an enemy. Two simple priority criteria for comparison of coalitions are suggested, and the corresponding preference restrictions based on appreciation of friends and aversion to enemies are...

This paper analyzes incentives for polluting firms to exchange abatement cost information under the non-linear pollution tax scheme ('differential tax') introduced by Kim and Chang [J. Regul. Econom. 5, 1993, 193-197]. It shows that polluting firms have - under mild conditions - an incentive to...

We adopt the largest consistent set defined by Chwe [J. of Econ. Theory 63 (1994), 299-235] to predict which coalition structures are possibly stable when players are farsighted. We also introduce a refinement, the largest cautious consistent set, based on the assumption that players are...