边际最优化模型的理论根源及其法学应用之检讨

The Theoretical Roots of Marginal Optimization Model and Its Legal Application

无论从实证层面还是规范层面,新古典经济学极具科学性和一般性的边际最优化模型都构成了法律的经济分析学派的核心理论框架。面对正交易成本的现实世界,法律的经济分析摒弃了基于比较权衡的经验主义传统的古典经济学,尝试采用新古典经济学的理论模型构建法律分析框架。立基于唯理主义传统的新古典经济学虽然借助微积分等数学工具构建了一个假设清晰、逻辑严密的最优均衡体系,但其追求最优结果的绝对性思考仅是一种理论建构。然而,实证经济学和规范经济学之间的逻辑关系隐含了一种否定前件的逻辑谬误,因此,新古典经济学的理论内含了逻辑谬误,经由科斯定理的理论转介,这一内含逻辑谬误的新古典经济学理论直接决定了法律的经济分析学说的理论构建,并间接决定了这一基于边际分析和最优化理论的理论框架在立法层面的规则制定与司法层面的法律适用等法学应用局限。

The marginal optimization model of neoclassical economics constitutes the core theorical framework in the economic analysis of law,whether from the positive level or the normative level.As the neoclassical economics based on the rationalism tradition abandons the classical economics based the empirical tradition,so it does not effectively explain the real world.Although the neoclassical economics sets up an optimal equilibrium system with the help of mathematical tools,such as calculus,but this absolute thinking to find the optimal result has become a kind of theoretical fictionalization.For example,the theory of optimal standardization in economic analysis of property law is a typical theoretic example of neoclassical economics based on the philosophy of rationalism“invading”the science of law.However,not only its five theoretical hypotheses,such as the externalized information cost,a new type of property rights trading market,the existence of the numerous types of property rights simultaneously,the incremental type of property rights in the real world only with the information cost and the frustration cost,and the perfect rationality and the perfect information of the decision-makers,cannot be tested by the real world,but also its logic of argumentation based on the internalization of externalized information costs cannot be justified.Based on the theoretical judgment,we find the logical relationship between positive economics and normative economics which is implied“the logical fallacy of denying the antecedent”.Also,we show that this logical fallacy determines the theoretical framework of economic analysis of law directly and the theoretical failure of its application in law indirectly by way of transition theory agent of the Coase theorem,whether the rule-making of legislative level or the application of law of judicial level.Specifically,1)economic analysis of law insists that the optimal standard that should have been achieved at zero transaction costs(the optimal amount of property rights,the optimal amount of prevention, the optimal amount of evidence, etc. ) is the natural goal for law to pursue, however,the problem lies in the fact that since the prerequisites for realizing the optimal standard are simplynot available, this normative pursuit not only lacks practical feasibility and legitimacy, but also lackssocial traditional roots and historical sense of institutional development. 2) in economic analysis oflaw, the role played by law is to try to design the optimal legal system in the corresponding costbenefitequation for x and y, respectively, to take the minimum value of the partial differential. Butthe problem is that in the real world there are no such absolutely optimal systems based on optimalcriteria. 3) in the marginal optimization model of legal economics, the law is seen as the“ savior” ofthe problem of negative externalities, and the legislator or judge has the ability to set different kindsof optimal standards to maximize social welfare or minimize social costs by internalizing externalcosts. The problem with this theoretical framework, however, is that it fails to examine specificlegal rules as a system at all, which leads to a complete failure to consider not only the costs ofdefining and operating the law, but also the difficulty of effectively assessing the real-world impact ofspecific legal systems.