Find the general conditions such that punishment can work in a linear public good game in the ERC model and the Fehr-Schmidt model. Hint: for the ERC model fi nd the level of punishment such that after she has paid for punishing Anna will have exactly the social reference point. For the Fehr-Schmidt model fi nd the level of punishment such that the free rider, Miguel, and punisher, Anna, will end up with the same material payoff.