Sunday, July 5, 2009

Prisoner’s Dilemma

Prisoner's dilemma is problem in a game theory. It was framed at RAND by Merill Flood and Melvin Dresher in 1950. Albert Tucker formalized the problem by adding the prisoner statements and giving name 'Prisoner's Dilemma'.
It touches various fields of science : evolution, game theory, cooperation, altruism, reciprocal altruism, moralism for some names.

The classic statement is :
'Two suspects are arrested by the police. The police have insufficient evidence for a conviction, and, having separated both prisoners, visit each of them to offer the same deal. If one testifies (defects from the other) for the prosecution against the other and the other remains silent (cooperates with the other), the betrayer goes free and the silent accomplice receives the full 10-year sentence. If both remain silent, both prisoners are sentenced to only six months in jail for a minor charge. If each betrays the other, each receives a five-year sentence. Each prisoner must choose to betray the other or to remain silent. Each one is assured that the other would not know about the betrayal before the end of the investigation. How should the prisoners act?'

We have an iterated version of the dilemma known as 'Iterated Prisoner's Dilemma'
Solutions:
I will be posting different strategy for PD and about its occurrences in future  posts.