【作者】 王凯；

【导师】 马庆国；

【作者基本信息】 浙江大学 ， 管理科学与工程， 2010， 博士

【摘要】 近年来,突发事件在全世界,特别是在人口众多且处于经济和社会转型期的中国频繁发生,对生命、财产和社会发展造成重大破坏。决策者的有效决策是应对突发事件的关键,但他们几乎难免被决策方案框架(表达形式)“迷惑”,对效用相同的方案因为其框架不同而做出不同选择,从而出现框架效应。框架效应最早由2002年诺贝尔经济学奖得主Kahneman及其合作者于1981年提出。作为“双刃剑”,框架效应一方面可能对决策产生负面影响,降低决策者应对突发事件的绩效；另一方面又可以被媒体合理利用,使决策者获得公众的支持。因此,突发事件下决策者的框架效应问题具有重要的研究价值。回顾已有研究,为了加深对突发事件下框架效应的理解,有两方面关键问题需要解决：1)突发事件下的框架效应是否存在,以及该效应的产生机理是什么?2)决策问题背景(对生命进行救援决策,或对货物进行救援决策)、决策者性别和情绪对该效应是否具有影响,以及产生这种影响的原因是什么?以解决上述问题为目的,本文以突发事件下的决策者为对象,完成了三项递进深入的研究。研究一继承了前人未对决策者明确施加决策时间压力的做法,采用问卷方式考察突发事件下的框架效应是否存在,以及决策问题背景和决策者性别对该效应的影响。研究一为本文与前人研究搭建了“沟通桥梁”,使本文结论能够与已有研究成果相比较。研究二在研究一的基础上,对决策者明确施加决策时间压力,使研究条件更加贴近真实的突发事件情境。在此情境下,该研究：1)借助ERP(事件相关电位)实验,从行为决策科学和决策神经科学两个层面解释突发事件下框架效应的产生机理；2)考察决策问题背景和决策者性别对框架效应的交互影响。研究三是对研究二的补充,它增加考察了负性偶然情绪(决策问题的外围因素诱发决策者产生的负性情绪)对突发事件下框架效应的影响,并借助ERP实验从神经科学层面解释了产生这种影响的原因。通过对三项研究各自结论的整合,本文从整体上得到如下重要结论：1)决策者应对突发事件的决策会受到决策方案框架的影响,产生框架效应,并因此而降低决策速度。2)就突发事件下对生命进行救援决策的男性决策者而言,决策时间压力对其框架效应有强化作用,使他们由不受到框架影响转变为出现经典的框架效应。3)决策问题背景和决策者性别对突发事件下的框架效应存在交互影响。当生命和货物同时需要救援时,无论决策者的性别如何,货物问题都无法引起他们的足够重视；相反,生命问题能够诱发决策者较高的决策动机,使男性决策者出现经典的双向框架效应,但却使女性决策者出现偏向风险的单向框架效应。4)在突发事件下对生命进行救援时,女性比男性决策者更容易受到决策框架影响,并且比男性决策者更冲动和冒险。无论是否受到决策时间压力,女性决策者都出现框架效应；而男性决策者只在承受决策时间压力时出现框架效应。此外,女性决策者在更短的时间内凭直觉决策,并且其风险偏好高于男性决策者。5)P2、N2、P3和N500这4个脑电成分的综合作用是决策者在突发事件下产生框架效应的神经科学机理。P2、N2、P3和N500波幅的变化意味着在同种(正性或负性)框架下,选择同等效用的确定性方案和风险方案之间,决策者的风险感知速度、决策冲突强度、决策难度和决策者对决策结果的不确定性存在显著差异。因此,决策者对确定性方案和风险方案做出不同选择,形成框架效应。6)负性偶然情绪使突发事件下的决策者在正性框架下更多的选择风险方案,而这种影响可以通过P2、N2、P3和N500波幅的变化来解释。同样是决策者在正性框架下选择确定性方案,与中性情绪相比,负性偶然情绪使P2、N2、P3和N500的波幅分别显著减小、增大、减小及增大。这意味着决策者的风险感知速度加快,决策冲突、难度和对结果的不确定性同时增大,从而降低他们在正性框架下选择确定性方案的可能性,使他们在正性框架下更多的选择风险方案。作为一次以决策神经科学方法为主,对突发事件下决策者框架效应问题的探索,本文的创新之处体现在以下4个方面：1)本文对决策者明确施加决策时间压力,并基于此发现对于在突发事件下进行生命救援决策的男性决策者而言,决策时间压力对框架效应具有强化作用。尽管前人强调决策时间压力是突发事件区别于非突发事件的显著标志,但他们并未对决策者明确施加决策时间压力,从而对突发事件情境的模拟效果存在不足。本文克服了这一局限,增强了本文结论对于突发事件的适用性,同时也将人们关于决策时间压力对框架效应强化作用的讨论背景延伸到突发事件领域。特别是本文有关决策时间压力在决策问题背景和决策者性别的共同调节下对框架效应产生强化作用的结论,推进了人们对于决策时间压力与框架效应之间关系的理解。2)本文借助ERP实验,从脑电成分的角度,解释了突发事件下框架效应的产生机理,使人们对此机理的认识由行为决策科学层面深入到决策神经科学层面。前人通过fMRI(功能核磁共振)实验讨论了投资问题中框架效应的产生机理,但其结论未必适用于突发事件情境。本文采取比fMRI下决策问题研究的ERP实验获得P2、N2、P3和N500成分的活动特征,并将其与行为决策科学理论相结合,使人们能够更全面和深入的理解突发事件下的框架效应,也为后人将ERP实验应用于突发事件下决策问题的研究提供了示范。3)本文发现和解释了突发事件下决策问题背景和决策者性别对框架效应的交互影响。前人分别单独考察了决策问题背景和决策者性别对突发事件下框架效应的影响,但并未将这两个因素同时纳入研究体系。本文弥补了这一缺憾,并从理论上建议突发事件应急管理工作应该对生命救援和货物救援分别处理,并且高度重视女性比男性决策者更加冲动和冒险,以及更易受决策框架影响的特点。4)本文发现负性偶然情绪能够使突发事件下的决策者在正性框架下的风险偏好显著增强,并借助ERP实验,从决策神经科学层面对此影响进行了解释。前人仅在消费者购买决策领域讨论负性偶然情绪对框架效应的影响。本文充分认识负性偶然情绪在突发事件下的普遍性,在突发事件领域考察和解释负性偶然情绪对框架效应的影响。根据研究结论,本文建议,为了防止应对突发事件的决策者过于冒险,应使他们尽量避免接触可能诱发负性偶然情绪的影音资料等素材,而使他们尽量针对决策问题本身进行思考。更多还原

【Abstract】 In recent years, more and more paroxysmal events have been happening frequently all over the world, especially in China, the country with a huge number of people during the period of economical and social transition. These events have caused significant damages to lives, properties and social development. Efficient decision making is the key to cope with such events. However, decision makes can hardly avoid framing effect, which means they make different choices on the alternatives with the same utility but various forms of presentations. Kahneman, who won the Nobel Prize for Economics in 2002, discovered framing effect with his collaborator in 1981. As a double edged sword, framing effect has negative effect on decision makers’performance under paroxysmal events, but can also be used properly by media to help decision makers winning public support. Therefore, it is of great value to research decision makers’framing effect under paroxysmal events.In order to understand the framing effect under paroxysmal events more profoundly, there are two important topics to discuss.1) Is there framing effect under paroxysmal events? If so, what is the mechanism of such effect? 2) Whether the decision problem domain (life or commodity), decision maker’s gender and emotion influence framing effect? If so, what is the mechanism of such influence? With the purpose to answer these questions, this thesis completes three studies step by step with the decision makers under paroxysmal events as research object.Following the literature, study 1 exerts no explicit time pressure on decision makers, and uses questionnaire to investigate whether framing effect exists and the influence of decision problem domain and decision maker’s gender on framing effect. This study is a bridge, making it possible to compare the current conclusions with the literature.Based on study 1, study 2 exerts time pressure explicitly on decision makers, which makes the research circumstances more similar to the reality. This study fulfills two tasks:1) explain the mechanism of framing effect under paroxysmal events with ERP (event-related potentials) experiment both on the behavioral and neural level; 2) study the interactive influence of decision problem domain and decision maker’s gender on framing effect under paroxysmal events.Study 3 is a complement to study 2. It focuses on the influence of negative incidental emotion (negative emotion induced by factors out of the current decision problems) on framing effect under paroxysmal events, and explain the mechanism of such influence on the level of decision neuroscience with ERP experiment.We can come to the following important conclusions based on the integration of conclusions from the three studies in this thesis.1) There is framing effect on decision makers under paroxysmal events, resulting in more slowly decision making.2) When the male decision makers are making decisions on lives problems under paroxysmal events, decision time pressure can strengthen the framing effect, drawing the male decision makers who were immune to decision frames into classical framing effect.3) The decision problem domain and gender have interactive effect on framing effect under paroxysmal events. When lives and commodities need rescuing simultaneously, the decision maker doesn’t attach enough importance to the commodities regardless of the gender. In contrast, lives saving problems induce higher decision motivation, leading classical framing effect in male decision makers and unidirectional framing effect of risk seeking in the females.4) Facing lives saving problems, the females are more prone to show framing effect and more impulse and risk seeking than male decision makers. Female decision makers show framing effect irrespective of decision time pressure. However, decision time pressure is a prerequisite to the male decision makers’framing effect. When it comes to female decision makers, they usually make intuitive decisions in shorter time, and show higher risk preference than male decision makers. 5) The comprehensive role of P2, N2, P3 and N500 is the neural mechanism for the framing effects under paroxysmal events. The changing of the amplitude of P2, N2, P3 and N500 indicates that there are significant differences of risk perception speed, decision conflict, and decision difficulty and decision makers’uncertainty with their decisions when decision makers make choices between the certain alternative and the risky alternative with the same utility under a certain frame. Due to these reasons, decision makers make different choice on the certain and the risky alternative, causing framing effect.6) The negative incidental emotion strengthens decision makers’risk preference under the negative frame, and such influence can be explained by the changes of the amplitude of P2, N2, P3 and N500. Compared to neutral emotion, when decision makers with negative incidental emotion choose the certain alternative under the positive frame, the amplitude of P2, N2, P3 and N500 decreases, increases, decreases and increases significantly. This means that the risk perception speed, decision conflict, decision difficulty and uncertainty with decision choice of the decision maker increase simultaneously and lead the decision maker more possible to choose risky alternative under the positive frame.As an exploration to framing effect under paroxysmal events mainly with the method of decision neuroscience, this thesis has four innovations.1) Decision time pressure is exerted on decision makers explicitly in this thesis, based on which the strengthening effect of decision time pressure on framing effect for male decision makers facing lives rescuing problems under paroxysmal events is discovered. Decision time pressure has been emphasized as the key factor to distinguish paroxysmal events from normal events in the literature, but no research has exerted decision time pressure explicitly on decision makers before. This thesis overcomes such limitation. It extends the discussion background of the strengthening effect of decision time pressure on framing effect to paroxysmal events, and gives people a deeper understanding of the relationship between decision time pressure and framing effect by finding the interactive role of decision problem domain and decision maker’s gender on such relationship.2) The mechanism of framing effect under paroxysmal events is explained under the perspective of brain potentials with ERP experiment in this thesis. The mechanism of framing effect in the domain of investment problems has been explained with fMRI experiment, but the conclusions may not be suitable to paroxysmal events. ERP experiment is more suitable to study decision problems under paroxysmal events than fMRI and is employed by this thesis. Taking the results of P2, N2, P3 and N500 of the ERP experiment and related theories of behavioral decision science together, this thesis reaches a more comprehensive and deeper understanding of framing effect under paroxysmal events. This thesis can also be taken as an example for the application of ERP experiment in the research of decision problems under paroxysmal events.3) The interactive effect between decision problem domain and the decision maker’s gender has been found and explained by this thesis. The main effect of decision problem domain and the decision maker’s gender has been discussed by scholars in the domain of paroxysmal events, but no research has taken these two factors into account simultaneously. This limitation has been overcome by this thesis. Lives and commodities should be treated separately under paroxysmal events has been suggested. Besides this, female is more impulsive, risk seeking and easier to be influenced by decision frames, which should be paid more attention in the paroxysmal events management.4) The negative incidental emotion has been found to significantly strengthen decision makers’risk preference under the positive frame, and such effect’s mechanism is explained by ERP experiment on the neuroscience level in this thesis. The literature discusses the influence of the negative incidental emotion on framing effect only in the domain of consumer purchasing decision. This thesis attaches importance to the prevalence of the negative incidental emotion under paroxysmal events, and conducts an ERP experiment on this topic. Based on the theoretical conclusions, it is suggested that decision makers under paroxysmal events should stay away from media information which is possible to induce the negative incidental emotion as far as possible and be encouraged to trade off the alternatives based on the problem itself.更多还原