新古典经济人三重特征的局限与重构

经济人是对现实中的人的抽象,是经济学分析的必要逻辑起点。新古典经济学的经典假设认为经济人是完全自利的,具有无限的计算能力,信息是完全的。显然,这分别是对人的行为动机、行为能力和行为环境三重特征的抽象。但是,这种抽象是片面的,建基于其上的经济理论对一些经济现象缺乏解释力,产生了一些"异象"。实际上,行为人具有自利和利他二维正交的双重动机;行为能力受主客观因素制约,从而具有固有的局限性;行为环境具有复杂性和不确定性,从而信息也是不可穷尽的。据此,可以重构出一个"现实经济人"假说。这一假说建立在认知科学、神经科学等自然科学的坚实基础上,它没有武断地假定永恒的人性特征;它抽象出了经济研究中人的三重特征的本质属性,并将新古典经济人作为特例纳入其中。以其为假设前提构建经济理论可以更好地解释和预测经济现象,并且具有重要的现实意义。

The Limitations of Homo Economicus of Neo-classical Economics and Its Reconstruction

Homo economicus is an Abstraction of realistic human beings and is a necessary logical starting point of economic analysis.Neoclassical economics’ homo economicus includes self-regarding motive,infinite calculating ability and perfect information.Its is an Abstraction on decision-makers’ three types of characters,which are behavioral motive,behavioral ability and behavioral surroundings.But this Abstraction is exparte,thus the economic theories based on it can not give convictive explanations for some economic phenomenon,which are called "anomalies".Researches verify that people have both self-regarding motive and altruistic motive.Also,In view of the newly developments of cognitive economics and neuroeconomics,we show that behavioral ability is inherently limited,and information can never be fully learned for surroundings is complex and uncertain.Based on our analysis,we reconstruct the "realistic homo economicus",which Abstracts the essential attributes of the three types of characters,and embodies the homo economicus of neoclassical economics as a special case.The economic theories based on it can give better explanations and forecasting,and this Abstraction also has important practical significance.