An economics professor discovered three students cheating on the final exam. Speaking to the students individually in his office, he gave each student two options:

1 If the student confessed, he or she would receive a zero on the final exam, but suffer no other consequences.

2 If the student did not confess, he or she would go before the Office of Student Judicial Affairs, and any confessions by the other two students would be used as evidence.

During the sessions in the professor’s office, one of the accused said, “This feels like you put me in a prisoners’ dilemma game.” By the end of the day, the professor had three confessions.

Question.

When does cooperation break down?