I understand the debt calculation as group-enforced punishment for defection. It’s a measure of how much punishment is due to bring the average utility of an opponent back down to expectation, after that opponent “steals” utility by defecting when they “should” cooperate. It’s not an actual debt, and not symmetrical around that average. In fact, in the temperature example, it should be considered NEGATIVE debt for someone to unilaterally set their temperature lower.
I understand the debt calculation as group-enforced punishment for defection. It’s a measure of how much punishment is due to bring the average utility of an opponent back down to expectation, after that opponent “steals” utility by defecting when they “should” cooperate. It’s not an actual debt, and not symmetrical around that average. In fact, in the temperature example, it should be considered NEGATIVE debt for someone to unilaterally set their temperature lower.