Prisoners Dilemma,囚徒困境 Dormitory 522,Classic Prisoners Dilemma,In 1950, Merrill Flood and Melvin Dresher work out the plight of related theory, then consultant Albert Tucker named the “prisoners dilemma“. Classic prisoners dilemma as follows:,Classic Prisoners Dilemma,Police arrested a, b two suspects, but dont have enough evidence to charge two men into sin. So the police separated imprisoned suspects, and respectively meet them, and provided both parties the following the same choice: if a man confessed and to be a prosecution witness (related terms says “betrayal“ each other), and the other party remain silent, this person will be released immediately, and the silent one will be sentenced to 10 years in prison.,Classic Prisoners Dilemma,If two people keep silent (related terms says “cooperation“ each other), the two people also sentenced to prison for 1 year. If two people debunk each other (related terms called each other “betrayal“), the two people also sentenced to eight years in prison. Use this form as follows:,Table 1,Analysis,Like other example of game theory, the prisoner dilemma assume that every participant (namely “prisoner“) are selfish, or seek their own maximum interests, and not enough to the interests of the other participants. Participants in one of the strategic interest income, if in any case are better than any other strategy, this strategy is called “the strict disadvantage”, rational participants would never choose. In addition, no other power intervene personal decisions, participants can be fully willing to choose according to his strategy.,Analysis,What strategy should the prisoner choose to put his own personal sentence narrowed to the shortest? Two prisoners are seperated , and do not know each other choice; And even if they can talk, or may not be able to do believe each other. The rational choice of individual character, against each other is better than to have lower total silence. Try imagine dilemma two rational prisoner might choose how: if the other person silent, betrayal will let my release, so I will betray. If the other side charges against me, and I shall charge each other to get lower sentence, so also will betray.,Analysis,Two people face the same situation , so two people rational consideration will be the same conclusion- choice of betrayal. Betraying is dominant strategy of the two strategies. Therefore, the game can only be reached Nash equilibrium, that is both sides participants rebelled against each other, the results were alike in eight years in prison.,财经词典,http:/finance.joy.cn/video/490319.htm,Question 1,Prisoners dilemma, two prisoners are in trouble, cant get ideal results, because what the prisoners care about is not the jail time itself but they do not want to go to jail longer than the other? 囚徒困境博弈中，两个囚徒之所以会处于困境，无法得到较理想的结果，是因为两囚徒都不在乎坐牢时间长短本身，只在乎不能比对方坐牢时间长？,Answer 1,Wrong. Conclusion is on the contrary, and the root is just because the prisoners care very much about the absolute time in prison. In addition, we start to assume two prisoners that are rational economic man, and rational economic man absolutely benefit themselves, not relative interests as the decision of the target. 结论恰恰相反，也就是囚徒困境博弈中两囚徒之所以出于困境，根源正是因为囚徒很在乎坐牢的绝对时间长短。此外，我们一开始就假设两囚徒都是理性经济人，而理性经济人都是以自身的绝对利益，而不是相对利益为决策目标的。,Thanks !,