Inequity aversion and advantage seeking with asymmetric competition

In this experiment I study a novel three-player ultimatum game in which two proposers with unequal amounts of money simultaneously submit offers to one responder, who may accept at most one offer. I compare the predictions of inequity aversion, advantage seeking, and self-interest. Unlike previously studied cases of symmetric proposer competition, the predictions of these models do not coincide in the asymmetric case. The experimental results show that responders sometimes accept the smaller offer, and the degree of asymmetry between proposers affects responder behavior. The results further suggest heterogeneity among responders, with advantage-seeking preferences occurring most frequently.