Over time, the wrong moves are penalized, and their users either learn by watching others or disappear. We get our monetary and fiscal policies right the same way that birds build their nests right.
作为进化的结果，这些经验法则还算有效（至少还在容忍范围之内）。随着时间的推移，错误的行动被惩罚，其使用者要么通过观察别人来学习、要么被淘汰。我们像鸟儿合理筑巢一样习得合理的货币和财政政策。