We show and explain how generosity beyond that explainable by social preferences can manifest in bargaining. We analyze an ultimata game with two parties vying to coalesce with a randomly chosen proposer. They simultaneously demand shares of the surplus. The proposer must then make an offer that...

A recent advance in our understanding of repeated PDs is the detection of a threshold d* at which laboratory subjects start to cooperate predictively. This threshold is substantially above the classic threshold "existence of Grim equilibrium" and has been characterized axiomatically by Blonski,...