【作者】 王立丹；

【导师】 水仁德；

【作者基本信息】 浙江大学 ， 应用心理学， 2010， 硕士

【摘要】 决策心理的研究是当前认知心理学领域的热点课题之一。决策研究领域中影响最广泛的理论——前景理论认为,个体在进行决策时依据的不是决策方案各种可能结果的绝对效用值,而是以某个既存的心理中立基点即参照点为基准,把决策结果理解为实际损益量与心理参照点的偏离方向和程度。许多研究发现,参照点并不是固定不变的,而是随着时间、先前的决策结果等因素而发生偏移。但是他们的研究大多涉及决策的客观因素,较少考虑到人的主观因素(如冒险倾向、认知偏差、人格因素等等)对参照点偏移的影响。其中决策者的冒险倾向是一个很重要的主观因素,很多研究发现冒险倾向确实能够对决策行为产生影响,然而这些研究并未深入探讨冒险倾向是如何影响决策者的决策行为。本研究假设,冒险倾向是通过影响参照点的偏移而影响最终的决策行为的。本研究通过三个实验,探讨了在股票投资领域冒险倾向对决策行为产生影响的机制。实验一采用纸笔测验范式研究了在理想的情况下、中间插入买卖操作的情况以及投资组合的情况下,冒险倾向对参照点偏移的影响；由于纸笔测验与真实的投资情景相差很大,并且模拟真实的投资场景又有很多限制因素,因此在实验二中我们对前人的BDM (Becker, G.M., Degroot, M. H.,& Marschak, J.1965)范式做了一些改进,来研究在三种不同的投资情景中,冒险倾向对参照点偏移的影响。为了验证在真实的股票交易中,人们的投资行为与前两个实验得出的结论是否一致,我们设计了实验三,股票价格的变化更接近真实,考察在这种情况下,冒险倾向对参照点偏移的影响。在每个实验开始之前,我们用冒险倾向问卷把被试分成了冒险和保守两组被试。三个实验的结果如下：(1)三个实验的结果都表明：在同等额的收益(6元)之后,参照点的偏移量大于损失(6元)之后参照点的偏移量。(2)在理想的投资情景中,纸笔测验表明：冒险组被试参照点的偏移量大于保守组,这一效应在收益的股票上更加明显；BDM范式研究结果表明,无论是收益还是损失的股票,冒险组被试参照点的偏移量都大于保守组。(3)在股票价格上涨或下跌之后,插入卖出和重新买入这一操作,无论在纸笔测验范式中还是BDM范式中,参照点的偏移量都要大于在理想的投资情景中参照点的偏移量；并且冒险倾向的主效应显著。(4)在投资组合的情景中,纸笔测验表明：在单只股票收益时,整体投资亏损的情况下参照点的偏移量大于整体投资盈利时的情况。冒险倾向对参照点的偏移并没有影响；而在BDM范式中,整体盈亏对单只股票参照点的偏移量并没有影响,但是冒险倾向的主效应显著。从三个实验的结果我们可以得出：冒险倾向对决策参照点的偏移有显著的影响,对于冒险的人来说,决策参照点的偏移量大于保守的人；同等额的收益之后参照点的偏移量大于同等额的损失之后参照点的偏移量；在投资组合的投资情景下,冒险倾向对参照点偏移的影响并没有得到一致的结果,说明在比较复杂的投资情景中,冒险倾向对人们投资行为的影响还需要进一步的研究。通过本研究,理论上我们对冒险倾向对决策行为产生影响的机制进行了初步探讨；对现实生活中人们的投资行为也有一定的指导意义。更多还原

【Abstract】 The investigation of decision-making is a focus in the field of cognitive psychology. Prospect theory-the most popular theory in decision-making concludes that people derive utility from gains and losses relative to a reference point, not from total wealth. Many studies have found that the reference point is not fixed, it update through time as a function of outcomes of past decisions or other factors. However, most investigations were related to objective factors in decision-making, with little consideration to subjective factors (such as risk propensity, cognitive bias and personality factors, etc.), which may influence reference point adaptation. Risk propensity, one of important subjective factors, can influence decision-making behavior, but these studies did not thoroughly investigate how it works. So, we suppose that risk propensity influence decision-making behavior through reference point adaptation.We design three experiments to explore the impact of risk propensity on reference point adaptation. Experiment 1 study the impact on reference point adaptation after prior gain and loss in ideal condition, the intervention with selling and repurchasing and portfolio cases using questionnaire experiments. Since written test and a real investment vary greatly, and simulate the real scenario is nearly impossible, therefore the second experiment we use BDM(Becker, GM, Degroot, MH,& Marschak, J.1965) paradigm which has been made some improvement to study the impact on the reference point adaptation in the three different investment situations, the same as in the experiment 1. In order to verify in a real stock trading, the impact of risk propensity on the reference point adaptation. In the experiment 3, the stock price changes day by day, to explore how risk propensity affect the reference adaptation. Before every experiment, the subjects were divided two groups: adventuresome subjects and conservative subjects, using the risk propensity questionnaire.From the three experiments we derive several results:(1) The magnitude of reference point adaptation is significantly greater following a gain than following a loss of equivalent size (6 yuan).(2) In the ideal investment condition, the experiment 1 using written test found that the adventuresome subjects’magnitude of reference adaptation was grater than the conservative subjects, when the prior outcome was gain; the experiment 2 using the BDM paradigm found the effect whenever the prior outcome was gain or loss.(3) After the stock price changed (gain or loss), we inserted the operation of selling and repurchase. The experiment 1 and 2’results show that the magnitude of reference point adaptation in this case was grater than in the ideal condition; In this case, the effect of risk propensity is very prominent in the experiment 1 and 2.(4) In the portfolio condition, the written test and BDM paradigm derived different results:the written test showed that the magnitude of reference point adaptation in the overall gain condition is smaller than in the overall loss condition; the effect of risk propensity is not prominent. However, the BDM paradigm found that the effect of risk propensity was prominent, and the overall gain or loss did not influence the reference adaptation.From the results we can conclude that:The magnitude of reference point adaptation is significantly greater following a gain than following a loss of equivalent size; and the magnitude of reference point adaptation in the ideal condition is smaller than in the condition intervention with selling and repurchase operation. In the two conditions, adventuresome subjects’magnitude of reference point adaptation grater than conservative subjects, proving that risk propensity affects the adaptation of reference point to influence the decision-making behavior. In the portfolio condition, the two paradigms contradict each other, indicating that further studies are needed to investigate the reference point adaptation in the complex context.Through this study, in theory, we preliminary investigate the mechanism how risk propensity affects decision-making behavior; in real life, the study enable us to understand the investors’ behavior better.更多还原