Coalition bargaining in four games that include a veto player

Tested the predictions of 3 models of coalition behavior. 120 graduate students played each of 4 games, rotating among the 5 player positions (including a veto player) between games. The games were played under 1 of 3 time pressure/default conditions: (a) no time pressure, (b) a condition such that the constant payoff to coalitions was lost if an agreement was not reached in 3 attempts, and (c) a condition such that the payoff for no agreement was fixed at 60 points for the veto player and 10 for the other players. The veto players' payoffs varied over games and tended to increase as play continued, at times approaching the entire payoff. Thus, the weighted probability (S. S. Komorita, 1974) and Roth-Shapley (A. E. Roth, 1977; L. S. Shapley, 1953) models were not supported; the core model received some support. The default conditions had little effect. The likelihood of socially beneficial behavior in competitively motivating situations is discussed.