We use a two-person public goods experiment to distinguish betweene±ciency and fairness as possible motivations for cooperative behavior.Asymmetric marginal per capita returns allow only the high-productivityplayer to increase group payo®s when contributing positive amounts....

This paper investigates distributive justice using a fourfold experimental design:The ignorance and the risk scenarios are combined with the self-concernand the umpire modes. We study behavioral switches between self-concernand umpire mode and investigate the goodness of ten standards of...