Characterizations of the choice functions that select the cores or the externally stable cores induced by an underlying revealed dominance digraph are provided. Relying on such characterizations, the basic order-theoretic structure of the corresponding sets of revealed cores is also analyzed

We investigate the computational complexity of several decision problems in hedonic coalition formation games and demonstrate that attaining stability in such games remains NP-hard even when they are additive. Precisely, we prove that when either core stability or strict core stability is under...

This paper studies the core of combined games, obtained by summing two coalitional games. It is shown that the set of balanced transferable utility games can be partitioned into equivalence classes of component games to determine whether the core of the combined game coincides with the sum of...

This paper presents synthetically some recent developments in the theory of coalition and network formation. For this purpose, some major equilibrium concepts recently introduced to model the formation of coalition structures and networks among players are briefly reviewed and discussed. A few...

This paper proposes axiomatic foundations of expectation formation rules, by which deviating players anticipate the reaction of external players in a partition function game. The projection rule is the only rule satisfying subset consistency and responsiveness to the original partition of...

This paper proposes a formulation of coalitional payoff possibilities in games with externalities, based on the assumption that forming coalitions can exploit a ”first mover advantage”. We derive a characteristic function and show that when outside players play their best response...

This paper presents some recent developments in the theory of coalition and network formation. For this purpose, a few major equilibrium concepts recently introduced to model the formation of coalition structures and networks among players are brie?y reviewed and discussed. Some economic...

In this paper we review a number of coalitional solution concepts for the analysis of the stability of cartels and mergers under oligopoly. We show that, although so far the industrial organization and the cooperative game-theoretic literature have proceeded somehow independently on this topic,...

This paper considers cooperative game theoretic settings in which forming coalitions can act as Stackelberg leaders. We de�fine a value function which modi�fies the gamma-value function (Hart & Kurz, 1983, Chander & Tulkens, 1997) by letting members of deviating coalitions move �first in...

We investigate the computational complexity of several decision problems in hedonic coalition formation games and demonstrate that attaining stability in such games remains NP-hard even when they are additive. Precisely, we prove that when either core stability or strict core stability is under...