The evolution of resilience
研究了一个社会演化模型，其中非排他性公共品能降低灾难概率，发现韧性类型在固定群体中无法与自私类型竞争，但在灾难减少人口时却能存活。
I analyze a social evolutionary model in which there is a non-excludable public good that reduces the chances of catastrophe. I show that while resilient types that produce the public good cannot survive head-to-head competition with other more selfish types in a fixed population, they do if catastrophes reduce population.