We analyse interethnic cooperation in an infinitely repeated prisoner's dilemma when members of one group are unable to target punishment towards individual defectors from the other group. We first show that indiscriminate outgroup punishment may sustain cooperation in this setting. Our main...

We analyse interethnic cooperation in an infinitely repeated prisoner’s dilemma when members of one group are unable to target punishment towards individual defectors from the other group. We first show that indiscriminate punishment may sustain cooperation in this setting. Our main result,...