效率、边际等式与成本分离

Efficiency, Marginal Equation and Cost Differentiation

理解真实世界各种现象和行为之道,在于寻找影响成本和收益的约束条件。考虑了所有的约束条件,经济总是有效率的,边际收益总是等于边际成本,私人成本与社会成本没有分离。现实中,帕累托改进是不存在的。帕累托改进要求约束条件不变,那些所谓的帕累托改进其实伴随了约束条件的改变,因而不是真正意义上的帕累托改进,也就不能成为无效率的理由了。

The efficiency of economy could be realized if marginal cost equals marginal benefit and social cost equals private cost. However, it will depend on the stability of restraint, which is impossible in real world. The so-called Pareto improvement is in fact an inefficient one.