Who gets it? An experimental study of non-monetary outside options in the ultimatum game

Sammanfattning: This thesis seeks to explore whether non-monetary outside options and a concern for the experimenter influence both proposer and responder behaviour in the ultimatum game. With pre-registered design and analysis plans, I run an experiment with students at the Stockholm School of Economics assigned to one control and two treatment groups, using a between subject design. In the first treatment, participants are informed that the rejection of the offer by the proposer leads to the destruction of the money. In the second treatment, players are informed that the rejected money will be given to a charity. My results show that responders are significantly affected by the treatments, reflecting that social welfare concerns for the experimenter do exist in an ultimatum game setting, contrary to popular belief. However, I cannot prove that non-monetary outside options have a significant effect on proposer behaviour. Overall, my results could have an impact on the way we interpret previous ultimatum game studies.