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...

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...

Can a court system conceivably control opportunistic behavior if judges are selected from the same population as ordinary citizens and thus are no better than the rest of us? This paper provides a new and, as we claim, quite profound rational choice answer to that unsolved riddle. Adopting an...

In the experimental scenario several agents repeatedly invest in n (n2) state-specific assets. The evolutionarily stable and equilibrium (Blume and Easley, 1992) portfolio for this situation requires to distribute funds according to the constant probabilities of the various states. The different...