De Jaegher Kris
Utrecht University School of Economics, Utrecht University, Kriekenpitplein 21-22, 3584 EC, Utrecht, The Netherlands.
Theor Popul Biol. 2017 Feb;113:1-12. doi: 10.1016/j.tpb.2016.09.003. Epub 2016 Sep 21.
The game-theoretic model in this paper provides micro-foundations for the effect a harsher environment on the probability of cooperation among multiple players. The harshness of the environment is alternatively measured by the degree of complementarity between the players' cooperative efforts in producing a public good, and by the number of attacks on an existing public good that the players can collectively defend, where it is shown that these two measures of the degree of adversity facing the players operate in a similar fashion. We show that the effect of the degree of adversity on the probability of cooperation is monotonous, and has an opposite sign for smaller and for larger cooperation costs. For intermediate cooperation costs, we show that the effect of a harsher environment on the probability of cooperation is hill-shaped.
本文中的博弈论模型为更恶劣的环境对多个参与者之间合作概率的影响提供了微观基础。环境的恶劣程度可以通过参与者在生产公共物品时合作努力的互补程度来衡量，也可以通过参与者能够集体防御的对现有公共物品的攻击次数来衡量，结果表明这两种衡量参与者所面临逆境程度的方式具有相似的作用机制。我们表明，逆境程度对合作概率的影响是单调的，并且对于较小和较大的合作成本具有相反的符号。对于中等合作成本，我们表明更恶劣的环境对合作概率的影响呈倒U形。
