Revisiting Strategic versus Non-Strategic Cooperation

We use a novel experimental design to disentangle strategically- and non-strategically-motivated cooperation. By using contingent responses in a repeated sequential prisoners' dilemma with a known probabilistic end, we differentiate end-game behavior from continuation behavior within individuals while controlling for expectations. This design allows us to determine the extent to which strategically-cooperating individuals are responsible for the so-called endgame effect. Experiments with two different subject pools indicate that the most common motive for cooperation in repeated games is strategic and that the extent to which endgame effects are driven by strategically-cooperating individuals depends on the profitability of cooperation