Players from two populations, predictors and predictees, are randomly matched in a game--theoretic version of Newcomb's Problem. Predictors are able to predict the predictees' choices by observing their type. There are two types of predictees, those who take their predictability into account by...

In evolutionary models of indirect reciprocity, reputation mechanisms can stabilize cooperation even in severe cooperation problems like the prisoner's dilemma. Under certain circumstances, conditionally cooperative strategies, which cooperate iff their partner has a good reputation, cannot be...