Ultimatum game

The ultimatum game is the game that has become the popular instrument of economic experiments. An early report is by Nobel laureate John Harsanyi in 1961. One player, the proposer, is endowed with a statement of money. The proposer is tasked with splitting it with another player, the responder. once the proposer communicates his decision, the responder may accept it or reject it. if the responder accepts, the money is split per the proposal; whether the responder rejects, both players get nothing. Both players know in extend the consequences of the responder accepting or rejecting the offer.

Variants

In the "competitive ultimatum game" there are numerous proposers and the responder can accept at almost one of their offers: With more than three naïve proposers the responder is usually offered near the entire endowment which would be the Nash Equilibrium assuming no collusion among proposers.

In the "ultimatum game with tipping", a tip is authorises from responder back to proposer, a feature of the trust game, & net splits tend to be more equitable.

The "reverse ultimatum game" authorises more energy to the responder by giving the proposer the modification to offer as numerous divisions of the endowment as they like. Now the game only ends when the responder accepts an offer or abandons the game, and therefore the proposer tends to receive slightly less than half of the initial endowment.

Incomplete information ultimatum games: Some authors hit studied variants of the ultimatum game in which either the proposer or the responder has private information approximately the size of the pie to be divided. These experiments connect the ultimatum game to principal-agent problems studied in contract theory.

The pirate game illustrates a variant with more than two participants with voting power, as illustrated in Ian Stewart's "A Puzzle for Pirates".