Information pictures
The prototype of the leading male actor in the oscar award-winning film " beautiful spirit " , nobel laureate john nash and his wife, died in a tragic accident on 24 may 2015. The man has passed, and let us together revisit his great discovery of economics — the nash balance — in memory of this great man who has fallen and fallen throughout his life。
Nash has evenly expanded the discipline of game theory from theory to reality, and is now widely applied to economics research, international trade, diplomatic games, and even philosophical theories. It is long gone beyond economics. Under the conditions of the non-cooperative balance, whereby the players in the game cannot communicate with each other, there is an information asymmetry, and when the nash balance is reached, everyone thinks that they have the highest advantage. In short, it's nice to see you. I'm good。
For example, the classic “conviction dilemma”, where two accomplices were arrested, a. And b., and tried in isolation (there was no exchange of information between them), the police condition was that if both were silent, they would both be sentenced to one year's imprisonment; if one was silent, another revealed him, the silent person would be sentenced to 20 years' imprisonment and the whistleblower would be acquitted; and if both denounced each other, both would be sentenced to five years' imprisonment. At that time, prisoners a and b had the following psychological activities:
If the other party chooses to remain silent and i choose to expose it, then i will be acquitted
2. If the other party chooses to expose it and i choose to do so, i shall be sentenced to only five years (lower term)
If i choose to remain silent, the other party is likely to denounce it and i will be sentenced to 20 years。
So, i chose to expose. The result of both sides reaching the nash balance through a game was to expose each other and were sentenced to five years。
It is worth mentioning that the nash balance ostensibly negates adam smith's “unseen hand” theory. Because nash’s equilibrium theory holds that the best strategy that everyone chooses in a non-cooperative game does not lead to the best in general. The doctrine of the invisible hand, on the other hand, argues that social interests can be maximized because everyone makes rational choices based on individual interests. Clearly, these two theories contradict each other。
However, the facts are not simple. In the case of “prisoners' plight”, while a and b confessions were not the best option for both, they were the best for third parties who were not involved in the game, i. E., the police, because they had succeeded in making a confession. Moreover, in reality, both players could share information, and both prisoners had the right to have a lawyer and to communicate their intentions through them, with the result that both could remain silent. All in all, nash is balanced between the interests of the players, which apply to non-cooperative games, and “unseen hands”. The theory takes into account the general interests of society, i. E., the situation in which both players and non-players are involved。
