Consider an environment with widespread externalities, and suppose that binding agreements can be written. We study coalition formation in such a setting. Our analysis proceeds by defining on a partition function an extensive form bargaining game. We establish the existence of a stationary...

In the study of farsighted coalitional behavior, a central role is played by the von Neumann-Morgenstern (1944) stable set and its modification that incorporates farsightedness. Such a modification was first proposed by Harsanyi (1974) and was recently reformulated by Ray and Vohra (2015). The...

A game of love and hate is one in which a player's payoff is a function of her own action and the payoffs of other players. For each action profile, the associated payoff profile solves an interdependent utility system, and if that solution is bounded and unique for every profile we call the...

Harsanyi (1974) criticized the von Neumann-Morgenstern notion of a stable set on the grounds that it implicitly assumes coalitions to be shortsighted in evaluating their prospects. He proposed a modification of the dominance relation to incorporate farsightedness. In doing so, however, Harsanyi...

This chapter surveys the sizable and growing literature on coalition formation. We refer to theories in which one or more groups of agents (“coalitions”) deliberately get together to jointly determine their actions. The defining idea of a coalition, in this chapter, is that of a group which...

We provide a characterization of virtual Bayesian implementation in pure strategies for environments satisfying no-total-indifference. A social choice function in such environments is virtually Bayesian implementable if and only if it satisfies incentive compatibility and a condition we term...

This paper provides a general overview of the literature on the core of an exchange economy with asymmetric information. Incentive compatibility is emphasized in studying core concepts at the ex ante and interim stage. The analysis includes issues of non-emptiness of the core as well as core...

In a differencial economy with quasi-linear utilities, monetary transfers facilitate the fulfilment of incentive compability constraints: the associated ex ante core is generically nonempty. However, we exhibit a well-behaved exchange economy in which this core is empty, even if goods are...

An appropriate (interim) notion of the core for an economy with incomplete information depends on the amount of information that coalitions can share. The coarse and fine core, as originally defined by Wilson (1978), correspond to two polar cases, involving no information sharing and arbitrary...

It is well known that a social choice function is truthfully implementable in Bayesian Nash equilibrium if and only if it is incentive compatible. However, in general it is not possible to rule out other equilibrium outcomes, and additional conditions, e.g., Bayesian monotonicity, are needed to...