Take-it or leave-it offers are probably as old as mankind. Our objective here is, first, to provide a, probably subjectively-colored, recollection of the initial ultimatum game experiment, its motivation and the immediate responses. Second, we discuss important extensions of the standard...

We modify the Acquiring-a-Company game to study lying in ultimatum bargaining. Privately informed sellers send messages about the alleged value of their company to potential buyers. Via random information leaks, buyers can learn the true value before proposing a price which the seller finally...

Despite recent advances in reputation technologies, it is not clear how reputation systems can affect human cooperation in social networks. Although it is known that two of the major mechanisms in the evolution of cooperation are spatial selection and reputation-based reciprocity, theoretical...

Intensive studies on indirect reciprocity have explored rational assessment rules for maintaining cooperation and several have demonstrated the effects of the stern-judging rule. Uchida and Sasaki demonstrated that the stern-judging rule is not suitable for maintaining cooperative regimes in...

In impunity games proposers, like allocators in dictator games, can take what they want; however, responders can refuse offers deemed unsatisfactory at own cost. We modify the impunity game via allowing offers to condition of another participant’s counterfactual generosity intention. For a...

In two-person generosity games, the proposer’s agreement payoff is exogenously given, whereas that of the responder is endogenously determined by the proposer’s choice of the pie size. In three-person generosity games, equal agreement payoffs for two of the players are either exogenously...

Indirect reciprocity is one of the major mechanisms driving the evolution of cooperation in human societies. There are two types of indirect reciprocity: upstream and downstream reciprocity. Cooperation in downstream reciprocity follows the pattern ‘You helped someone, and I will help you’,...