Group egoism; investigating collective action and individual rationality

The paper discusses rationality at two levels. According to a common opinion the key to rationality at the group level is a willingness to contribute unselfishly at the individual level. I claim that even when rationality at the individual level is denied, it is often achieved by social punishment. The difficulty to organize a social project is exaggerated. The relative ease of implementing individual rationality has the disadvantage of frequently establishing and maintaining social order that, despite some enthusiastic proponents, fails to deliver rationality at the group level.