Evolution in Imperfect Commitment Bargaining - Strategic versus Ignorant Types

To commit in bargaining is crucial: In the ultimatum game with its one-sided commitment power the "proposer" (almost) receives the whole pie while the "responder" is left with (almost) nothing. When bargaining parties commit simultaneously the symmetric Nash (1950)-bargaining solution predicts equal shares. Continuously connecting these two games yields a one-parameter family of games (Fischer, Güth, Müller and Stiehler (2005)) for which we distinguish two behavioural dispositions, namely (1) neglecting commitment power and (2) reacting to it strategically. Their payoff implications define the evolutionary setup for which we derive the evolutionarily stable behavioral disposition. Our analysis sheds light on the hypothesis that in experiments participants neglect strategic aspects like commitment power.
JEL-classification: C72; C78
Keywords: bargaining, imperfect commitment, ultimatum game, Nash demand game, evolutionary game theory.