现代经典金融学的困境与行为金融学的崛起

The Puzzles of Modern Classical Financial Theory and the Development of Behavioral Finance

现代经典金融学从理性经济人假设出发 ,利用一般均衡分析和无套利分析演绎出一套相当完美的金融学理论。由于现实中人们的实际决策行为与“理性经济人”的假设有着较大差异 ,现代经典金融学遇到一些被称为“未解之谜”的现实问题。行为金融学以心理学对人们实际决策行为的研究成果为基础 ,丰富了对未解之谜的解释 ,逐渐成为金融学研究中的一个重要领域。从研究方法上看 ,行为金融学与现代经典金融学类似 ,即在某种假设的基础上建立模型 ,对金融市场的现象做出的解释。由于人们的实际决策行为具有强烈的状态依赖性 ,行为金融学在不同的状态下对人们的决策行为做出不同的假设和解释是合理的 ,而试图为行为金融学建立一个像经典金融学那样的统一框架是相对困难的。

Using models in which agents are rational, the modern classical financial theory explains financial markets in general equilibrium or no arbitrage framework. However, the human decisions are far from the rational assumptions in reality, there are many puzzles that the modern classical financial theory can't fully explain. Based on the arguments of the psychology research, behavioral finance models give the puzzles some reasonable explanations and become the important research fields of finance. Behavioral finance research is similar with modern classical finance research on methodology, for all of them start with assumptions of human decision. Since the decision behavior is influenced by the state of human, it is reasonable that behavioral finance models provide the different explanations at different state and it is difficult to form a uniform analysis framework for behavioral finance.