博弈论完整课件[浙江大学]__GAME_Cha

players receive payoffs that depend on the
combination of actions just chosen. Within the
class of such static (or simultaneous-move)
games,we restrict attention to games of
Chapter 1 完全信息静态博弈
Static Games of Complete Information
In this chapter we consider games of the
following simple form: first, the players
simultaneously choose actions; then, the
＊Two suspects are arrested and charged with
a crime. The police lack sufficient evidence to
convict the suspects, unless at least one
confesses.The police hold the suspects in
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Definition: The normal-form representation of an-n-player game specifies the players’ strategy spaces S1 , … , Sn and their payoff functions u1 ,…, un. We denote this game by G={S1, … ,Sn;u1, … , un}. 教材 Ｐ22
＊理解完全信息静态博弈时要注意事项
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１ Although we stated that in a normalform game the players choose their strategies simultaneously , this does not imply that the parties necessarily act simultaneously :it suffices that each choose his or her action without knowledge of the others’ choices, as would be the case “the prisoners’dilemma” if the prisoners reached decisions at arbitrary times (在任意时间)while in their separate cells.
complete information. That 可编辑ppt
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is each player’s payoff function (the function that determines the players payoff from the combination of actions chosen by the players) is common knowledge among all the players. 教材P21
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招认 囚徒１
沉默
囚徒２ 招认 沉默 –5, -5 0, -8
-8, 0 -1Βιβλιοθήκη Baidu, -1
囚徒的困境
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We now turn to the general case. The normal-form representation of a game specifies: (1)the players in the game;(2)the strategies available to each player;(3)the payoff received by each player for each combination of strategies that could be chosen by the players.
separate cells and explain the consequences
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that will follow from the actions they could take. If neither confesses then both will be convicted of a minor offense and sentenced to one year in jail. If both confess then both will be sentenced to jail five years. Finally, if one confesses but the other does not, then the confessor will be released immediately but the other will be sentenced to eight years in jail—five for the crime and a further three for obstructing justice(干扰司法)。
一、Normal-Form Representation
of Games and Nash Equilibrium
(一)Normal-Form Representation of Games
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In the normal-form representation of a game ,each player simultaneously chooses a strategy, and the combination of strategies chosen by the players determines a payoff for each player. We illustrate the normal-form representation with a classical example—The prisoners’ Dilemma.