Dictator game and Ultimatum game

万得福

Dictator game
http://en.wikipedia.org/wiki/Dictator_game
In the dictator game, the first player, "the proposer", determines an allocation (split) of some endowment (such as a cash prize). The second player, "the responder", simply receives the remainder of the endowment left by the proposer. The responder's role is entirely passive (the responder has no strategic input into the outcome of the game). As a result, the dictator game is not formally a proper game (as the term is used in game theory). To be a proper game, every player's outcome must depend on the actions of at least one other's. Since the proposer's outcome depends only on his own actions, this situation is one of decision theory. Despite this formal point, the dictator game is used in the game theory literature as a degenerate game. This game has been used to test the homo economicus model of individual behavior: if individuals were only concerned with their own economic well being, proposers (acting as dictators) would allocate the entire good to themselves and give nothing to the responder.

Adults' and childrens' behavior in dictator games
Experimental results have indicated that adults often allocate money to the responders, reducing the amount of money they receive.[4] These results appear robust: for example, Henrich, et al. discovered in a wide cross cultural study that proposers do allocate a non-zero share of the endowment to the responder.[5] Children also tend to allocate some of a resource to a recipient, and most five year olds share at least half of their goods

If these experiments appropriately reflect individuals' preferences outside of the laboratory, these results appear to demonstrate that either:
1.Proposers fail to maximize their own expected utility,
2.Proposers' utility functions may include non-tangible harms they incur (for example self-image or anticipated negative views of others in society), or
3.Proposers' utility functions may include benefits received by others.

Additional experiments have shown that subjects maintain a high degree of consistency across multiple versions of the dictator game in which the cost of giving varies. This suggests that dictator game behavior is, in fact, altruism instead of the failure of optimizing behavior.[clarification needed] Other experiments have shown a relationship between political participation and dictator game giving, suggesting that it may be an externally valid indicator of concern for the well-being of others.

Ultimatum game
http://en.wikipedia.org/wiki/Ultimatum_game

The ultimatum game is a game often played in economic experiments in which two players interact to decide how to divide a sum of money that is given to them. The first player proposes how to divide the sum between the two players, and the second player can either accept or reject this proposal. If the second player rejects, neither player receives anything. If the second player accepts, the money is split according to the proposal. The game is played only once so that reciprocation is not an issue.

In industrializedcultures, people offer "fair" (i.e., 50:50) splits, and offers of less than 20% are often rejected.One limited study on monozygotic and dizygotic twins claims that genetic variation can affect reactions to unfair offers, though the study failed to employ actual controls for environmental differences. It has also been found that delaying the responder's decision makes people reject "unfair" offers much less often.

kaleege

有意思。

我比较感兴趣的是dictator game的变化形式，我觉得其中的反对理由2是很强的，即“面子”问题，这个爱面子往往是下意识的。
要排除反对理由2，可以搞这样一种变化：游戏者不直接见面，而是通过网络或者短信来对话。因为不直接见面可以一定程度上减轻“面子”的顾虑。

万得福

呵呵，都是常识，现在用科学实验的方法表述出来。

archers

mark