Four theories of cooperation: the astounding failure to explain the restart effect

This paper draws a four-way classification of theories of cooperation, where they try to remedy the shortcoming of each other. Nonetheless, the four cannot easily explain the restart effect, the bizarre pulse upwards of cooperation after the participants have just defected in a finitely repeated prisoner’s dilemma game. The restart effect demonstrates that participants did not learn from the previous collapse, even when they are rematched with the same partners. While different theories have proposed different solutions of the anomaly, this paper shows that they are unsatisfactory, as they focus on the set preferences, defined narrowly as about either self-interest or other-interest (altruism). This paper stresses that we need instead to focus on commitment à la Amartya Sen: commitment is the execution of principles that are contrary to preferences (interests). This does not only allow us to understand the restart effect, but also cooperation in finite prisoner’s dilemma games.