Fowler James H
Department of Political Science, University of California at Davis, One Shields Avenue, Davis, California 95616, USA
Nature. 2005 Sep 22;437(7058):E8; discussion E8-9. doi: 10.1038/nature04201.
Panchanathan and Boyd describe a model of indirect reciprocity in which mutual aid among cooperators can promote large-scale human cooperation without succumbing to a second-order free-riding problem (whereby individuals receive but do not give aid). However, the model does not include second-order free riders as one of the possible behavioural types. Here I present a simplified version of their model to demonstrate how cooperation unravels if second-round defectors enter the population, and this shows that the free-riding problem remains unsolved.
潘查纳坦和博伊德描述了一种间接互惠模型,在该模型中,合作者之间的互助能够促进大规模的人类合作,而不会陷入二阶搭便车问题(即个体接受但不给予帮助)。然而,该模型并未将二阶搭便车者作为可能的行为类型之一纳入其中。在此,我展示他们模型的一个简化版本,以说明如果第二轮背叛者进入群体,合作将如何瓦解,这表明搭便车问题仍然没有得到解决。