Repeated prisoner's dilemma
You and a randomly chosen
co-player for several rounds of the prisoner?s dilemma game. After each
round a dice is thrown: if it shows 6, the game is stopped. Otherwise,
you will play another round with the same co-player.
In every round, each can
opt either for cooperation or defection. If both choose to cooperate, both
get 3 points each. If you both choose to defect, you get 1 point each.
If you choose defect and the other cooperate, you receive 5 points and
your co-player nothing. Conversely, if you cooperate and the other defects,
you receive nothing and the co-player gets 5 points.
Number of players: 22 (11 games)
Time evolution of mean payoff and frequencies
of R, S, T and P:
Most players learn during the game to defect.
Thereby their payoff decreases.
If the game extends further, many learn to cooperate, however.
Three games with persistent mutual cooperation.
Two games where a unilateral defect occurred in the last round.
The overall frequency of cooperate and defect is 75% to 25%.
The repetitions increase cooperation from 50% to 75%.
Written by Christoph Hauert