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...

This paper reinterprets the ? -core (Chander and Tulkens (1995, 1997)) and justifies it as well as its prediction that the efficient coalition structure is stable in terms of the coalition formation theory. It is assumed that coalitions can freely merge or break apart, are farsighted (that is,...

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 introduces a model of coalition formation with claims. It assumes that agents have claims over the outputs they could produce by forming coalitions. Outputs, insufficient to meet the claims and are rationed by a rule whose proposals of division induce each agent to rank the coalitions...

We model the process of coalition formation in the 16th German Bundestag as a hedonic coalition formation game. In order to induce players' preferences in the game we apply the Shapley value of the simple game describing all winning coalitions in the Bundestag. Using different stability notions...

We are concerned with the problem of core membership testing for hedonic coalition formation games, which is to decide whether a certain coalition structure belongs to the core of a given game. We show that this problem is co-NP complete when players' preferences are additive.