期望效用理论是现实生活的决策基础吗?——基于前景理论的反思

Is Expected Utility Theory the Foundation of Decision-Making in Reality?——A Reflection from Prospect Theory

现代主流经济学将不确定下的决策建立在期望效用理论之上,但大量的行为或选择悖论却对期望效用理论提出了挑战。事实上,人类行为并非追求期望效用最大化,而是包含了对风险的规避;风险厌恶也并非是普遍定律,而是更为凸显损失厌恶;同一问题也并非有相同决策,而是受不同框架的影响;决策权重与概率也不同,存在非线性关系;心理买价和心理卖价也不同,存在明显的禀赋效应;人们的选择与其评价往往也不一致,会出现偏好逆转现象。基于这些悖论,卡尼曼等提出了前景理论,它比预期效用理论更贴近现实,也更有利于理解和解释现实行为。

Modern mainstream economics takes expected utility theory as the foundation of decision-making under uncertainty.However,a lot of behavior or choice paradoxes put forward the challenge to expected utility theory.In fact,human behavior does not pursue the maximization of expected utility,but contains the evasion of risks;risk aversion is not common law, but loss aversion is more highlight;the same problem does not have the same decision,but influenced by the different framework;decision weight is different from probability,there is nonlinear relationship;psychological purchase price and sale price is different,there is obvious endowment effect;people＇s choice is always not consistent with his evaluation,preference reversal phenomenon will appear.Based on these paradoxes,Kahneman puts forward the prospect theory which is more close to reality than expected utility theory,as well as is more conducive to understand and interpret the real behaviors.