Ozono Hiroki, Kamijo Yoshio, Shimizu Kazumi
Faculty of Law, Economics and Humanities, Kagoshima University, 1-21-24, Korimoto, Kagoshima-shi, Kagoshima-ken, 890-0065, Japan.
School of Economics and Management, Kochi University of Technology, 2-22, Eikokuji-Cho, Kochi-Shi, Kochi-Ken, 780-8515, Japan.
Sci Rep. 2017 Oct 30;7(1):14379. doi: 10.1038/s41598-017-13918-8.
Second-order free riders, who do not owe punishment cost to first-order free riders in public goods games, lead to low cooperation. Previous studies suggest that for stable cooperation, it is critical to have a pool punishment system with second-order punishment, which gathers resources from group members and punishes second-order free riders as well as first-order free riders. In this study, we focus on the priority of punishment. We hypothesize that the pool punishment system that prioritizes second-order punishment is more likely to achieve cooperation than the system that prioritizes first-order punishment, because the former is more likely to obtain sufficient punishment resources. In the experiments, we compare four pool punishment systems: 1To2 (first-order punishment to second-order punishment), 2To1 (second-order punishment to first-order punishment), 1ONLY (first-order punishment only), and 2ONLY (second-order punishment only). We find that the 2To1 and 2ONLY systems can receive more support than the 1To2 and 1ONLY systems and only the 2To1 system can achieve high cooperation. However, the effect of priority of second-order punishment is observed only when the punishment ratio (PR) is low (Experiment 1), not high (Experiment 2), in which the punishment resource is relatively abundant.
在公共物品博弈中，二阶搭便车者不向一阶搭便车者支付惩罚成本，这会导致合作水平较低。先前的研究表明，对于稳定的合作而言，拥有一个带有二阶惩罚的群体惩罚系统至关重要，该系统从群体成员那里收集资源，并惩罚二阶搭便车者和一阶搭便车者。在本研究中，我们关注惩罚的优先级。我们假设，优先进行二阶惩罚的群体惩罚系统比优先进行一阶惩罚的系统更有可能实现合作，因为前者更有可能获得足够的惩罚资源。在实验中，我们比较了四种群体惩罚系统：1对2（一阶惩罚对二阶惩罚）、2对1（二阶惩罚对一阶惩罚）、仅1（仅一阶惩罚）和仅2（仅二阶惩罚）。我们发现，2对1和仅2系统比1对2和仅1系统能获得更多支持，并且只有2对1系统能实现高度合作。然而，只有当惩罚率（PR）较低时（实验1），而非较高时（实验2，此时惩罚资源相对丰富），才会观察到二阶惩罚优先级的效果。
