模糊规避的形成机制：基于可评价性假设的视角

模糊规避是指在相同奖赏的情况下,决策者会力图规避从主观上判断具有模糊概率的事件而偏好具有相同精确概率的事件。本研究使用同时评价、单独评价的研究范式从随机事件和自然事件两个领域来探讨模糊规避的形成机制。研究结果表明,当风险事件和模糊事件同时评价时,个体倾向于模糊规避;当风险事件和模糊事件单独评价时,模糊规避会消失。     

概率大小、损益结果和认知闭合需要对模糊规避的影响

模糊规避是指在相同奖赏的情况下,决策者会力图规避从主观上判断具有模糊概率的事件而偏好具有相同精确概率的事件。本研究探讨了概率大小、损益结果和认知闭合需要对模糊规避的影响。研究发现,在小概率受益的情况下,个体倾向于模糊寻求;在中概率受益的情况下,个体倾向于模糊规避;在高概率受益的情况下,个体倾向于模糊规避;在小概率损失的情况下,个体倾向于模糊规避;在中概率损失的情况下,个体倾向于模糊规避;在高概率损失的情况下,个体倾向于模糊寻求。但是,研究并未发现认知闭合需要对模糊规避有预测作用。     

不确定性容忍度对模糊决策中决策偏好的影响及其情景依赖性*

研究以Ellsberg选瓶任务为决策材料,探讨了不同任务特征下个体不确定性容忍度对模糊决策中决策偏好的影响。结果发现,获益情景下:高概率时高、低容忍度个体对模糊选项的选择无显著差异,均偏好模糊规避;中概率时低容忍度个体比高容忍度个体表现出更低程度的模糊规避,前者倾向于模糊中立,后者倾向于模糊规避;低概率时两者对模糊选项的选择无显著差异,均倾向于模糊中立。损失情景下:高概率时两者对模糊选项的选择无显著差异,均倾向于模糊寻求;中概率时低容忍度比高容忍度个体更偏好模糊寻求,前者倾向于模糊寻求,后者倾向于模糊中立;低概率时两者对模糊选项的选择无显著差异,均倾向于模糊规避。这表明,不确定性容忍度对模糊决策偏好产生作用,但这种作用会受到损益概率和损益结果的影响,具有情景依赖性。     

概率水平与模糊性对短视损失规避的影响

短视损失规避是指如果投资者频繁地评估其投资回报,那么他就会经常改变其投资决策,进而减少对风险资产的投入。本文采用实验法探讨了任务概率水平以及模糊性对短视损失规避的影响。结果发现短视损失规避只存在于中等损失概率任务中,说明该现象并非普遍存在;当概率模糊时,高损失概率任务中出现短视损失规避,而低损失概率任务中则出现反向的短视损失规避,说明模糊性能扩展“短视”起作用的概率范围。     

风险来源与决策:背信规避现象及人际联结需求的作用

经典的风险决策研究及相关理论模型关注人们如何对以不同概率出现的损益结果进行评价与选择,但很少区分和探究在相同概率和损益值下不同风险来源对决策的影响。事实上,决策情境中的风险既可能源自客观因素,也可能源自人为因素。与相同大小的客观风险相比,人们更规避人为风险,这种现象被称为"背信规避"。本研究采用信任博弈任务,通过最小可接受概率法和决策选择法两种方式探讨风险来源对决策冒险性的影响。结果发现:(1)中国被试存在"背信规避"现象,即对人为风险的规避程度高于客观风险;(2)当恐惧情绪被唤起时,被试对人为风险的规避程度降低,使得背信规避现象消失,甚至出现"反背信规避"倾向;(3)人际联结需求影响背信规避,人为风险下人际联结需求中介了恐惧情绪对决策冒险性的影响。上述结果有助于加深我们对风险来源影响决策的现象及其机制的理解。     

概率公共信念的动态刻画（英文）

Robert Aumann的不一致的达成定理揭示了如果两个主体关于某事件E具有相同的先验概率,并且利用私人信息更新了他们关于事件的概率,那么,若事件的后验概率是他们之间的公共知识,则这个后验值一定是相同的。而Dov Monderer和Dov Samet考虑了包含有关于公共知识概率赋值的一种变体,推广了奥曼这个结论。在这篇文章中,笔者基于概率和动态认知逻辑,采用多种方法考察了关于他们结论的动态刻画。本文主要的目标是构建一个模型,可以描述随着主体彼此间的交互深入和环境变化,主体知识和信念所发生的变化。同时,笔者表明这种逻辑框架对于研究交互社会群体中主体信念改变的动态进程是富足和灵活的。     

经验决策：概念、研究和展望

传统风险决策研究范式中, 决策信息是事先限定的, 即在决策之前呈现各个决策选项的概率和收益, 被试基于这些信息进行决策。已有研究表明, 在传统风险决策任务中人们会高估小概率事件(rare event)。然而最近出现的一种基于不完整信息的决策形式, 即经验决策却对这一发现提出了挑战。研究发现, 人们在进行经验决策时会表现出对小概率事件的低估, 经验决策和传统决策形式之间存在差异。本文主要介绍经验决策的概念及其研究, 并从学习和不确定程度等角度对两种决策形式进行再认识, 以进一步理解经验决策并提出展望。     

儿童“期望值”判断的研究

以 7岁、9岁、12岁小学生和成人大学生为被试 ,让他们在 5种实验任务中进行期望值判断 ,以探讨儿童期望值判断的发展。结果表明 :(1) 7岁儿童就能够在简单任务中进行概率推理和正确判断事件的期望值 ;(2 )儿童对概率和价值两个维度相乘关系的认知呈现发展趋势 ,但其乘法规则的运用仍逊于成人水平。而成人期望值判断的成绩有较大的个体差异。 (3)在期望值相同的情况下 ,儿童更注重事件发生的概率而相对忽视价值     

Linda问题：“齐当别”抉择模型的解释

大量有关人类归因判断的研究表明,人类经常违反理性概率公理。Tversky和Kahneman（1983）使用Linda问题等特定场景的研究发现,人们系统性地表现出违反理性推断标准,判断合取事件发生概率大于其组成事件发生概率,称之为合取谬误,并用人们使用代表性启发式判断概率来解释该现象产生的原因。然而使用启发式观点对合取谬误现象进行解释过于模糊不清。该文首先介绍了合取谬误现象及其解释模型,然后应用Li（1994,2004）提出的不确定情形下决策理论——“齐当别”抉择模型对Linda问题中合取谬误产生的原因进行了新的解释     

主体关联性对贝叶斯推理概率估计的影响

用贝叶斯推理问题为实验材料,探讨了主体关联性对贝叶斯推理概率估计的影响。结果表明,当估计的事件与主体有关时,被试对消极事件概率估计较低,对积极事件概率估计值;当估计的事件与主体无关时,被试对消极事件和积极事件的概率估计无显著差异。反应时分析表明,被试对消极事件的概率估计比对积极事件的概率估计时间显著地长,当消极事件与主体有关时概率估计时间就更长;而对积极事件的概率估计,与主体有关和与主体无关时反应时差异不显著。这表明,被试对消极事件的概率估计(特别是消极事件与己有关时)更为慎重。     

Ambiguity Attitudes over Time

Previous research demonstrates that individuals exhibit a stronger level of ambiguity aversion for high probabilities than for low probabilities. Given that risky and ambiguous prospects are often unresolved until a future date (e.g., investment decisions, new product launches, and medical interventions), this study examines the impact of time on ambiguity preferences at different probability levels. Our experimental results indicate that although ambiguity preferences for low‐probability events remain constant, a robust effect of time occurs for high‐probability events. More specifically, temporal distance mitigates ambiguity aversion. This effect is consistent for different elicitation methods (preference rating and probability–ambiguity trade‐off tasks). We propose a dual‐process model (affective versus cognitive processing styles) to explain our results. Affective processing for high‐probability lotteries resolved in the current period increases ambiguity aversion, while cognitive processing leads to less ambiguity‐averse choices for future lotteries. Copyright © 2015 John Wiley & Sons, Ltd.     

Career Decision Ambiguity Tolerance Scale: Construction and initial validations

The Career Decision Ambiguity Tolerance Scale (CDAT) measures individual evaluations of and responses to ambiguity encountered in career decision making. It was developed and initially validated through two studies of college students. An exploratory and confirmatory factor analysis consistently showed a three-factor structure for career decision ambiguity tolerance, consisting of preference, tolerance, and aversion. In addition to support for construct validity and subscale reliabilities, the findings also support the scale's incremental validity in predicting career indecision, career decision-making self-efficacy, and career adaptability over and beyond general ambiguity tolerance. The theoretical meaning and practical application of the CDAT were discussed along with its limitations and suggestions for future research.     

On the composition of risk preference and belief

Prospect theory assumes nonadditive decision weights for preferences over risky gambles. Such decision weights generalize additive probabilities. This article proposes a decomposition of decision weights into a component reflecting risk attitude and a new component depending on belief. The decomposition is based on an observable preference condition and does not use other empirical primitives such as statements of judged probabilities. The preference condition is confirmed by most of the experimental findings in the literature. The implied properties of the belief component suggest that, besides the often-studied ambiguity aversion (a motivational factor reflecting a general aversion to unknown probabilities), perceptual and cognitive limitations play a role: It is harder to distinguish among various levels of likelihood, and to process them differently, when probabilities are unknown than when they are known.     

Ambiguity attitudes in qualitative contexts: The role of prior beliefs

Most studies of ambiguity aversion rely on experimental paradigms involving monetary bets. Thus, the extent to which ambiguity aversion occurs outside of such contexts is much less understood, particularly when the situation cannot easily be reduced to numerical terms. The present work seeks to understand whether people prefer to avoid ambiguous decisions in a variety of different qualitative domains (e.g., work, family, love, friendship, exercise, study, and health), and, if so, to determine the role played by prior beliefs in those domains. Across three studies, we presented participants with 24 vignettes and measured the degree to which they preferred risk to ambiguity in each. We also asked them for their prior probability estimates about the likely outcomes in the ambiguous events. Ambiguity aversion was observed in the vast majority of vignettes, but at different magnitudes. It was predicted by whether the vignette involved gain or loss as well as by people's prior beliefs; however, the heterogeneity between people meant that the role of prior beliefs was only evident in an individual-level analysis (i.e., not at the group level). Our results suggest that the desire to avoid ambiguity occurs in a wide variety of qualitative contexts but to different degrees for different people and may be partially driven by unfavorable prior estimates of the likely outcomes of the ambiguous events.     

模糊决策的情境依赖性

实验1采用艾尔斯伯格悖论的研究范式,探究被试对模糊的厌恶倾向以及在决策过程中所采用的决策策略。结果发现：被试对确定选项和模糊选项的选择存在差异;在肯定形式下倾向于确定选项,而在否定形式下则倾向于模糊选项,采用了利益最大化策略。实验2采用艾尔斯伯格悖论的变式,通过操纵概率和任务类型,发现：模糊决策具有情境依赖性,并非任何情况下个体都厌恶模糊。当风险选项不能满足自己的需要,即获胜机率比较小时,人们会偏向模糊选项。     

The Effects of Skewed Probability on Decision Making under Ambiguity

Studies have shown that many decision makers knowingly contradict the Savage Postulates when event probabilities are ambiguous, typically displaying ambiguity aversion. For the purposes of this paper, ambiguity is defined operationally as a subjective second-order distribution on probabilities, f(p). Most studies to date on ambiguity have focused on symmetric second-order distributions, demonstrating preference effects of the mean and range or variance of f(p). This research asserts that choice behavior is also significantly and systematically impacted by the skewness of f(p). An experiment using 130 MBA students revealed that subjects are often ambiguity averse when f(p) is negatively skewed but ambiguity seeking when the skewness is positive, even though the mean and variance of f(p) remain constant. These skewness effects are incorporated into a model of choice under ambiguity.