公共品的起源、论题与逻辑

文章的目的是对公共品研究中的理解分歧作出一些澄清。笔者的分析是基于思想史和历史。通过对公共品理论的思想史梳理,笔者认为公共品的实质是一种兼具外部性与"搭便车"难题的物品或服务。而萨缪尔森式的研究由于将制度因素从公共品现象中剥离,致使公共品认知出现诸多混乱。针对实验经济学中兴起的公共品博弈,笔者以《大宪章》为例作了历史考察,发现从成本角度而言,公共品供给的行动逻辑是个体为减少外部成本或者为获取外部收益,通过承担私人成本的方式,提供具有外部性的物品或服务。但这一逻辑无法验证社会偏好理论的有效性,因为该理论更多地反映出一种价值判断而非事实陈述。

The Origin,Arguments, and Logic of Public Goods

This article is to clarify some confusions of the theory of public goods. Our analysis is based on the history of England, and the history of economic thought. After reviewing the history of public goods theory, we argue that the nature of public goods is the goods or services which have externalities, and people will be free riders when consume these goods or services. The absence institutional analysis, causes a lot of misunderstandings of public goods. In the second part of this article, we examine the history of Magna Carta, to find out the logic of an individual's act, when he is willing to provide public goods. Our conclusion is that, when the private cost is less than the external cost, there will be a motivation for the individuals to provide public goods. And it does not require any kind of social preferences.