ESS,NIS and GIS for matrix games in n‐species systems

In this paper, we discuss the concepts of evolutionarily stable strategy (ESS), neighborhood invader strategy (NIS) and global invader strategy (GIS) in n‐species systems. We give their definitions both on system level and species level. Although the definition on system level and that on species level are apparently different, it is found that they are equivalent to one another. About the relationships among an ESS, an NIS and a GIS for n‐species systems, we obtain the results similar to the ones for single species models: a GIS must be an NIS; an NIS must be an ESS; an ESS may not be a GIS; a GIS must be unique. The stability in the frequency dynamics with two phenotypes is also considered and the global stability of a GIS is shown. Copyright © 2010 John Wiley & Sons, Ltd.     

两人进化博弈策略的决定机制与应用研究

通过建立一般情况下的两人进化博弈模型,给出了系统均衡点对应的矩阵行列式和迹表达式的经济含义,分析了16种典型情形下的进化稳定策略,详细讨论了均衡点稳定性分析结果所对应的博弈双方决策过程,从策略权衡的视角揭示了策略选择的内在机制。研究结果表明:不同策略前提下的相对净支付决定了系统的进化稳定策略,对方的策略选择以及自身可选策略的支付比较是影响博弈主体策略选择的两个基本要素,博弈主体会趋向于选择在对方策略既定下能够带来更大支付的策略。最后以环境治理中地方政府与企业以及地方政府之间的博弈关系为例,从对称博弈和非对称博弈两方面阐明了本文所构建模型在政策设计中的应用价值:针对不同案例,只要明确了两人博弈的支付矩阵,就可以通过计算相对净支付确定博弈双方的行为演化规律和稳定策略,从而简化计算过程,更加直接和更为便捷地为政策设计提供理论参考。