Do you think that the tit-for-tat strategy will be successful in maintaining cooperation in cases where the repeated prisoners dilemma is being played with a finite time horizon (i.e. players know when the game will end)? Explain.
Article: "The prisoners' dilemma tournament
Imagine that you are playing a game of prisoners' dilemma with a person being 'questioned' in a separate room. Moreover, imagine that you are going to play not once but many times. Your score at the end of the game is the total number of years in jail. You would like to make this score as small as possible. What strategy would you play? Would you begin by confessing or remaining silent? How would the other player's actions affect your subsequent decisions about confessing?
Repeated prisoners' dilemma is a complicated game. To encourage cooperation, players must penalise each other for not cooperating. Yet the strategy described earlier for Jack and Jill's water cartel - defect forever as soon as the other player defects - is not very forgiving. In a game repeated many times, a strategy that allows players to return to the cooperative outcome fter a period of non-cooperation may be preferable.
To see what strategies work best, political scientist Robert Axelrod held a tournament. People entered by sending computer programs designed to play repeated prisoners' dilemma. Each program then played the game against all the other programs. The 'winner' was the programs that received the fewest total years in jail.
The winner turned out to be a simple strategy called tit-for-tat. According to tit-for-tat, a player should start by cooperating and then do whatever the other player did last time. Thus, a tit-for-tat player cooperates until the other player defects;he then defects until the other player cooperates again. In other words, this strategy starts out friendly, penalises unfriendly players and forgives them if warranted. To Axelrod's surprise, this simple strategy did better than all the more complicated strategies that people had sent in.
The tit-for-tat strategy has a long history. It is essentially the biblical strategy of 'an eye for an eye, a tooth for a tooth'. The prinsoners' dilemma tournament sugest that this may be a good rle of thumb for playing some of the games of life.