Strategy choice in the infinitely repeated prisoners' dilemma

We use a novel experimental design to identify the subjects' strategies in an infinitely repeated prisoners' dilemma experiment. We ask subjects to design strategies that will play in their place. We find that eliciting strategies has negligible effects on their behavior, supporting the validity of this method. We find the chosen strategies include some common ones such as Tit-For-Tat and Grim trigger. However, other strategies that are considered to have desirable properties, such as Win-Stay-Lose-Shift, are not prevalent. We also find that the strategies used to support cooperation change with the parameters of the game. Finally, our results confirm that long-run miscoordination can arise.