Decentralized versus collective bargaining - An experimental study

Two parties X, and Y, can either bargain separately with a third party Z or merge to become XY and bargain collectively with Z. Depending on the payoff implications of the two possible contracts and on the asymmetry inherent in the conflict payoffs of X and Y collective bargaining will increase, decrease or leave constant what X and Y achieve together. In the experiment, first X and Y vote for or against collective bargaining and then negotiate accordingly. Participants react adequately to strategic aspects, but not as predicted by the (Nash-)bargaining solution.