引言:一个公共牧场,有若于牧民在放牧,每个牧民都有两种选择:一是大家合作,有意识地控制各处的牲畜头数,使之与牧场的承载力相适应;一是尽可能多地增加自己拥有的牲畜头数。显然,当每个牧民都采用第二种策略,眼下也许会给自己带来更多的收益。然而,如果大家都这样无限制地增加 Introduction: In a public pasture, if pastoralists are grazing, each herder has two choices: First, we must cooperate and consciously control the number of livestock in various places so that it can adapt to the carrying capacity of pastures; It may increase the number of her own livestock. Obviously, when each herdsmen adopts the second strategy, they may now bring more benefits to themselves. However, if everyone increases this way without limit