Replication and Reinterpretation of "Equilibrium Play in Voluntary Ultimatum Games: Beneficence Cannot Be Extorted'"

Abstract

Smith and Wilson (2018) report an experiment involving a modified ultimatum game wherein the responder decides whether or not to participate in the game. They note that adding this option results in play closer to sub-game perfect predictions than previously observed. They suggest their results are explained by a model of decision-making rooted in Smith (1759). However, in Smith and Wilson (2018), the results of this play are contrasted against stylized facts from the literature, rather than statistically compared with an analogous control treatment. To ensure their interpretation is warranted, we conducted experiments of both their augmented game and a standard ultimatum game. Results from our augmented ultimatum game are consistent with those reported in Smith and Wilson (2018); however, there is no statistical difference between these results and those from the standard ultimatum game sessions. This highlights the need to include appropriate control treatments in experimental designs.

Keywords: Ultimatum game, Replication, Adam Smith