Bargaining and Buyout

I introduce a noncooperative coalitional bargaining model for characteristic function form games. A player not only buys out other players' resources and rights with upfront transfers as in Gul (Econometrica, 1989), but also strategically chooses partners instead of bargaining with a randomly selected opponent. Such transactions among players are interpreted as coalition formation. The main theorem provides a general inefficiency result. If a characteristic function form game has a strict subcoalition with a strictly positive worth and a player with a strictly positive marginal contribution to the grand-coalition, then an efficient stationary subgame perfect equilibrium does not exist, as long as the discount factor is sufficiently high but strictly less than 1. Two special results are established. A grand-coalition equilibrium is impossible when players are sufficiently patient, unless the characteristic function form game is a unanimity game. For a simple game with a veto player and multiple winning coalitions, a non-minimal winning coalition is formed with positive probability. In two applications, I study players' strategic alliance behavior and the effect of the strategic behavior on inequality. First, for three-player simple games, the equilibrium payoff vector Lorenz-dominates both the Shapley-Shubik power index and the core-constrained Nash bargaining solution. Second, for wage bargaining games, workers endogenously form a union and their equilibrium payoffs can be greater than marginal products.