Coalition Formation with Binding Agreements

Abstract

We study coalition formation in “real time”, a situation in which coalition formation is intertwined with the ongoing receipt of pay-offs. Agreements are assumed to be permanently binding: They can only be altered with the full consent of existing signatories. For characteristic function games we prove that equilibrium processes—whether or not these are history dependent—must converge to efficient absorbing states. For three-player games with externalities each player has enough veto power that a general efficiency result can be established. However, there exist four-player games in which all Markov equilibria are inefficient from every initial condition, despite the ability to write permanently binding agreements. Copyright 2007, Wiley-Blackwell.