Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We experimentally study the effect of a third-person enforcement on a one-shot prisoner’s dilemma game played by two persons, with whom the third person plays repeated prisoner’s dilemma games. We find that when the third person can observe these two persons’ play, the possibility of the third person’s future punishment causes them to cooperate in the one-shot game.