巨灾保险需求视角下致市场失灵的非理性行为

　　摘要

　　目前许多国家逐渐形成适应其自身情形的巨灾保险制度。然而,巨灾保险在发展过程中总会出现市场失灵的现象,巨灾保险的供给和需求低于人们的预期或者呈现非理性特征,这严重影响了巨灾保险的发展。

　　本文站在巨灾保险需求的角度分析导致市场失灵的非理性行为。传统需求理论决策的基础是“完全理性”假设下的期望效用理论,然而现实经济活动中却出现与此相悖的现象。于是本文引入行为经济学,认为个体在面临损失时却变得风险偏好,加之人们对小概率事件存在侥幸心理,导致巨灾保险需求的不足;另外,可得性偏差和显着性偏差导致投保人给予最近的信息较大的权重而忽略较早的信息,使得个人对风险的判断较主观。

　　在此基础上,本文以美国居民购买洪水保险的决策为例具体分析后一种非理性行为。首先,本文将“预期”这一行为经济学要素加入了传统期望效用理论模型,认为居民对洪水保险的购买量与其对洪水灾害发生概率的预期是正相关的,而居民对洪水灾害发生概率的预期在其对洪水灾害的观察中学习形成,并同过每次观察的洪水灾害来更新之前的“预期”。这一过程文章引入了修正的Beta-BernoulliBayesian学习模型,认为人们具有“健忘性”并对过去的信息按照一定的折旧率“ S ”进行折旧,因此越近的信息对人们的影响越大。

　　接着,本文采用美国的数据,建立了各期洪水灾害造成损失对保单购买量影响的固定效应模型。实证结果表明,洪水灾害发生对洪水保险需求的影响会持续9年,并且影响程度会逐渐减弱,这证明了本文对居民非理性行为的分析。

　　最后,本文提出在实际考量巨灾保险需求时要将行为经济学因素加入分析模型当中。而对于我国的巨灾保险来说,可以利用这种巨灾保险需求中的非理性行为,在灾后适时推进巨灾保险,并建立有效的风险反馈机制,建立强制或半强制的巨灾保险制度。

　　关键词:美国洪水保险;需求非理性;行为经济学

　　Abstract

　　By now many countries have formed their own catastrophe insurance systemsuitable to their own situation. However, there is always market failure during thedevelopment of catastrophe insurance, such as the supply and demand falling short ofpeople's expectation or being irrational, which hinders the development of catastropheinsurance greatly.

　　This paper analyzes irrational behaviors that lead to market feilures from theangle of demand of catastrophe insurance. The basis of traditional demand theory isexpected utility under the assumption of C6perfect rationality" which is not quite inaccordance with the real economic activities. According to theories of behavioraleconomics, the reason for insufficient demand for catastrophe insurance is that peoplebecome less risk-averse when faced with losses and they tend to take chances whenthe probability of losses is small. Besides,availability bias makes people give moreweight to recent information and ignore earlier information, which leads to subjectiveestimate of risks.

　　Based on this theory, this paper analyzes the latter irrationality taking Americanresidents' decision-making of buying flood insurance as an example. Firstly, thispaper add the economics element "expectation" into traditional expected utility model,assuming residents' purchase of flood insurance is positively correlated with theirexpectation of the probability of flood,which is formed from earlier observation offlood and they update their "expectation" each time they observe a new flood. Weintroduce the Modified Beta-Bernoulli Bayesian Learning model during this processand regard people as forgetful and discount past information with rate ” S”,whichimplies that newer information has larger influence on people's decision-making.

　　Then we use data from America to build a fixed-effect model to estimate theeffect of damages caused by each flood on the policy purchases of catastropheinsurance. The result shows that flood catastrophe has a 9-year declining effect on thedemand for flood insurance, which confirms our analysis of residents' irrationalbehavior.

　　In the last, this paper tries to add behavioral economics element into the modelwhen studying catastrophe insurance demand. For China, we can take advantage ofthis irrationality in catastrophe insurance to promote catastrophe insurance afterdisasters and build an efficient risk feedback mechanism to fiilly utilize government'srole in regulating the market.

　　Key words: the US flood insurance; irrational; behavioral economics

    目录

　　绪论

　　第一节选题背景和意义

　　第二节文献综述

　　一、国外研究状况

　　二、国内研究状况

　　第三节研究思路和本文结构

　　一、研究思路

　　二、本文结构

　　第四节创新点与不足

　　一、创新点

　　二、不足之处

　　第一章巨灾保险的发展

　　第一节巨灾保险的发展现状

　　第二节巨灾保险发展中的问题:市场失灵

　　第二章巨灾保险需求理论分析一从需求角度解释市场失灵

　　第一节巨灾保险需求传统分析

　　第二节行为经济学视角下巨灾保险需求分析

　　第三章美国洪水保险需求非理性行为分析

　　第一节美国洪水保险项目(NFIP)介绍

　　一、美国洪水保险运营模式

　　二、美国洪水保险产品特点

　　第二节居民对洪水保险需求的模型分析

　　一、居民的期望效用模型

　　二、居民Beta-BernoulliBayesian学习模型及其修正

　　第四章居民非理性行为对美国洪水保险需求影响的实证分析

　　第一节样本的选取

　　第二节变量的选取

　　第三节模型的建立

　　第四节实证结果

　　第五章结论与建议

　　第一节 结论

　　第二节对我国巨灾保险发展的建议

　　一、把握灾后时机推进巨灾保险

　　二、建立风险反馈机制

　　三、建立强制或半强制的巨灾保险机制

　　参考文献

　　致谢