预期理论权重函数π的由来、质疑及Tversky的阐释

THE DEDUCTION OF A DECISION WEIGHT π:CONTROVERSIES,QUESTIONS,AND ANSWERS

借助权重函数π的导出,Kahneman和Tversky解释了一些期望效用理论无法预测和描述的抉择(如艾勒悖论),使预期理论成为风险条件下行为决策的重要描述性模型.文章回顾了推导权重函数的基本假设及权重函数各特性的推导过程,介绍沿用相同的推导逻辑提出的对该函数特性的质疑,及Tversky对质疑的回应和解释.冀透过对权重函数的审视,将质疑的焦点转向最大化原则本身.

A weighting ftmction π was developed by prospect theory to explain that Allais Paradox arises because people behave so as to maximize overall value rather than EU. The way that the decision weight π was derived from choices was reviewed. The controversies and questions to the propoesd properties of subadditive, overweighted low probabilities, subcertainty and subproportionality were presented and discussed with Tversky＇ s own wxplanation and answers. An attempt was made to draw the research attention from which function was being maximized to whether people behave as if they are trying to maximize“something”.