再探框架对风险决策行为的影响

期望理论运用Ｓ状的价值函数和非线性的权重函数来解释和预测框架效应。“齐当别”抉择模型将不同框架下的抉择行为简单地看成是“最好可能结果之间的取舍”或者“最坏可能结果之间的取舍”。本研究设计了一“匹配”技术,并用此对作者所报告过的支持框架效应与不支持框架效应的选择问题加以再检验。实验表明,采用不同的框架并不能预测性地决定不同的抉择偏爱,而匹配结果所示的“齐当别”策略则能更好地对所收集到的有关框架效应的数据作出解释。     

艾勒悖论再探——三结果决策的齐当别式表征:“好-坏”抑或“最好-最坏”?

艾勒悖论的第一项决策任务属于三结果决策任务,这对齐当别模型以及鉴别其不同判断任务间的优势都具有特殊意义。本研究通过3项子研究系统的探讨了不同表征方式("最好-最坏","好-坏")、不同判断任务(经典判断任务与联合判断任务)、不同数量级的结果值(万元级、百万元级以及亿元级)以及不同决策情境(迫选,非迫选)上,齐当别模型对艾勒悖论的解释力。结果显示:无论是迫选情境还是非迫选情境,经典的艾勒悖论均可被齐当别模型解释,但应基于"好-坏"而非"最好-最坏"表征维度;齐当别模型的联合判断任务在三结果决策任务上的预测力也再次被证明优于经典判断任务。     

迫选规则体验法: 检验规范性和描述性风险决策理论的新尝试

为寻求检验规范性和描述性风险决策理论的通用标准, 本研究以期望价值理论和齐当别抉择模型为例, 探讨了“迫选规则体验法”的适用性。被试为120名大学生, 实验任务为要求被试分别完成自主决策(采用未知规则: 真规则)和规则迫选决策(遵循给定规则: 假规则)任务, 并对决策后的情感和认可程度进行评定。研究发现: (1) 被试在自主决策条件下比在规则迫选条件下体验到的正性情感程度更强, 负性情感的程度更弱; (2) 被试在自主决策与规则迫选决策两种条件下做出的相同决策越多, 该被试对迫选规则更加认可并体验到的正性情感程度越强, 负性情感的程度越弱; (3) 与期望价值理论相比, 齐当别抉择模型可能符合更多决策者的实际决策规则。这些结果表明, 作为检验规范性和描述性风险决策理论的新尝试, 迫选规则体验法可能更有助于回答“决策者实际采用的决策规则是什么”的问题。     

有限理性的"占优启发式"和"齐当别"决策模型的作为——当Allais悖论杠杆撬动了期望效用理论

人们在做决策时常常要受到时间或知识的限制,有时还要受到其双重限制。关于人们是如何进行风险决策,早期有期望效用理论对其加以解释,但Allais悖论对其标准化地位提出了挑战。Simon的“有限理性”观点提出后,一些研究者开始致力于开发决策的“有限理性”模型。文章讨论并比较了无限理性的期望效用理论被Allais悖论杠杆撬动之后,有限理性的“占优启发式”和“齐当别”决策模型所能做的和所不能做的。两种模型的决策标准、计算策略以及未来研究的展望也一并作了讨论。     

有限理性的“占优启发式”和“齐当别”决策模型的作为 ——当Allais悖论杠杆撬动了期望效用理论

人们在做决策时常常要受到时间或知识的限制,有时还要受到其双重限制。关于人们是如何进行风险决策,早期有期望效用理论对其加以解释,但Allais悖论对其标准化地位提出了挑战。Simon的“有限理性”观点提出后,一些研究者开始致力于开发决策的“有限理性”模型。文章讨论并比较了无限理性的期望效用理论被Allais悖论杠杆撬动之后,有限理性的“占优启发式”和“齐当别”决策模型所能做的和所不能做的。两种模型的决策标准、计算策略以及未来研究的展望也一并作了讨论     

决策中损益值大小效应的发生条件及机制再探 —— 一种齐当别视角及兼对视角本身的一些探讨

通过两个研究,损益值大小效应在1元~1亿元的广阔范围内,以及在只采用选择反应模式的条件下得到了进一步探讨,其机制也在齐当别模型的全新视角下得到了讨论;此外,齐当别模型本身以及模型的经典判断任务也得到了探讨。结果发现：基于选择反应模式时,损益值大小效应在获得情景中稳定存在,并只存在一个风险倾向的拐点,而它在损失情景中则不存在;损益值大小效应的机制能够被齐当别模型很好的解释;齐当别模型的经典判断任务对模型预测效能的检验力不足,但其与新设计的维度内判断任务联合后却有很大改善;齐当别模型对损失情景中的均含0结果值的决策任务的解释力还有待进一步探讨     

决策中损益值大小效应的发生条件及机制再探——一种齐当别视角及兼对视角本身的一些探

通过两个研究,损益值大小效应在1元～1亿元的广阔范围内,以及在只采用选择反应模式的条件下得到了进一步探讨,其机制也在齐当别模型的全新视角下得到了讨论;此外,齐当别模型本身以及模型的经典判断任务也得到了探讨.结果发现:基于选择反应模式时,损益值大小效应在获得情景中稳定存在,并只存在一个风险倾向的拐点,而它在损失情景中则不存在;损益值大小效应的机制能够被齐当别模型很好地解释;齐当别模型的经典判断任务对模型预测效能的检验力不足,但其与新设计的维度内判断任务联合后却有很大改善;齐当别模型对损失情景中的均含0结果值的决策任务的解释力还有待进一步探讨.     

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     

整合模型还是占优启发式模型? 从齐当别模型视角进行的检验

实验从齐当别模型的视角,通过对决策过程反应时的考察分别对以累积预期理论(cumulative prospect theory)为代表的整合模型和启发式模型家族的重要成员--占优启发式模型(priority heuristic)--进行检验。结果表明,决策过程反应时并未随着占优启发式模型所假定的决策步骤的增加而变慢;也未随着选项之间整体值差值的变大而变快;模糊决策过程的反应时反而快于风险决策过程的反应时。无论是以累积预期理论为代表的整合模型还是占优启发式模型均不能满意地描述和解释人们的实际决策过程,而齐当别模型则能解释大部分实验结果。文章建议多角度、多指标探讨人们的决策过程,检验、修改、完善,以及建立新的启发式模型或决策过程模型(process model),以增进对人们如何进行风险决策的理解。     

决策中的图形框架效应

决策框架效应作为一种违背不变性原则的非理性偏差, 已经得到研究的广泛证实。本研究突破了传统研究中主要由语言描述引发框架效应的限制, 从图形表征这一新的视角对图形框架效应做了深入探讨。本研究共包括6个实验, 通过操纵选项在不同图形表征版本中物理属性差异的突出性, 发现在表达信息不变的情况下, 人们判断和决策的偏好会受到图形表征的影响, 即出现了图形框架效应。研究结果表明, 图形框架效应普遍存在于各种决策情境以及各种图形表征方式中。基于属性替代理论和齐当别原则, 我们提出了一种解释图形框架效应内部作用机制的两阶段心理加工模型--图形编辑的齐当别模型(The Graph-edited Equate-to-differentiate Model, GEM)。     

The effects of payout and probability magnitude on the Allais paradox

The Allais paradox decision bias was first offered as a challenge to the expected utility theory over 60 years ago. Although the Allais paradox is a standard challenge for normative theories of risky choice, its causes are not well understood. The present experiment uses two manipulations of the Allais paradox to investigate the commonly proposed probability-weighting explanation of the paradox. Reducing the magnitude of the outcomes did not affect the size of the Allais paradox, contradicting previous literature and supporting the probability weighting hypothesis. Reducing the probability of the nonzero outcomes to eliminate certainty reduced, but did not eliminate, the Allais paradox, a result inconsistent with probability weighting and other theories of the Allais paradox. The results suggest that the certainty effect alone cannot explain the Allais paradox.     

确定、不确定及风险状态下选择反转:“齐当别”选择方式的解释

应用广义“弱优势”（weak dominance）模型检验确定、不确定及风险状态下的选择反转现象。该模型将人们的二择一选择行为描述为一种搜寻一备择方案在主观上优越于另一备择方案的过程。即：在甲方案在某一维度上优越于乙方案,而乙方案在另一维度上优越于甲方案的情况下,为了利用“弱优势”（weak dominance）原则达成决策,人们必须在一维度上将两者间较小的差异人为地“齐同”掉,而在另一维度上将“辨别”两者间较大的差异作为最终选择的依据。因此,在每次选择时,如果不认为最大的差异都是来自同一维度,就会导致选择反转。此项研究设计了一“匹配”任务,并借此检验,在不同的决策状态下,判断两备择方案在各维度上的差异是否能预测人们的重复选择变异。总的测试-再测试结果支持“齐当别”选择方式的解释。其发现表明：重复选择之所以可能是一致的,并不是因为每次都认定被选中的备择方案具有最大值,而是因为每次选择都认定最大的差异来自一固定的维度。     

The Common Ratio Effect in Choice,Pricing, and Happiness Tasks

The Allais common ratio effect is one of the most robust violations of rational decision making under risk. In this paper, we conduct a novel test of the common ratio effect in which we elicit preferences for the common ratio choice alternatives in choice, pricing, and happiness rating tasks. We find large shifts in preference patterns across tasks, both within and between subjects. In particular, we find that both the consistency and distribution of responses differ systematically across tasks, with modal choices replicating the Allais preference pattern, modal happiness ratings exhibiting consistent risk aversion, and modal prices maximizing expected value. We discuss the predictions of various cognitive explanations of the common ratio effect in the context of our experiment. We find that a dual process framework provides the most complete account of our results. Surprisingly, we also find that although the Allais pattern was the modal behavior in the choice task, none of the 158 respondents in our experiment exhibited the Allais pattern simultaneously in choice, happiness, and pricing tasks. Our results constitute a new paradox for the leading theories of choice under risk. Copyright © 2017 John Wiley & Sons, Ltd.     

What is wrong with Allais' Certainty Effect?

Several choice situations are constructed to explore whether the violation of expected utility theory in an Allais paradox choice situation can be attributed to what Tversky and Kahneman (1986) describe as the Allais certainty effect. Problems are developed where the Allais certainty effect would be expected to occur but results show it does not. Other problems demonstrate that the Allais ‘paradox’ is observed in the absence of the Allais certainty effect. The study concludes that, although expected utility theory is known to be wrong through the Allais paradox, the Allais certainty effect does not appear to be able to rescue it.     

More learned irrelevance than perseveration errors in rule shifting in healthy subjects

The present experiments examined the extent to which two possible sources of error affect healthy subjects' performance in a rule-shift task. All 115 participants first received a discrimination learning task, in which a pair of different visual stimuli was presented on each trial, one of which had to be identified as 'correct.' Each stimulus varied in two dimensions: a task-relevant and a task-irrelevant dimension. Feedback on correctness was given after each choice. After eight successive correct choices, the nature of the task-relevant dimension changed: the post-shift learning phase. Two types of error can occur in this phase: continued responding to the former relevant, but now irrelevant, dimension, a perseverative error, and non-responding to the former irrelevant, but now relevant, dimension, an error due to learned irrelevance. Different groups received a post-shift task in which none, one, or both of these two types of error could affect performance. The number of incorrect choices in the post-shift phase was significantly affected by learned-irrelevance errors but not by perseverative errors. An associative-learning model incorporating feedback-induced changes in both associative strength and saliency of the elements comprising the stimuli can explain these results.     

Sub-Optimal Choice by Pigeons: Failure to Support The Allais Paradox

Pigeons show a preference for an alternative that provides them with discriminative stimuli (sometimes a stimulus that predicts reinforcement and at other times a stimulus that predicts the absence of reinforcement) over an alternative that provides them with nondiscriminative stimuli, even if the nondiscriminative stimulus alternative is associated with 2.5 times as much reinforcement (Stagner & Zentall, 2010). In Experiment 1 we found that the delay to reinforcement associated with the nondiscriminative stimuli could be reduced by almost one half before the pigeons were indifferent between the two alternatives. In Experiment 2 we tested the hypothesis that the preference for the discriminative stimulus alternative resulted from the fact that, like humans, the pigeons were attracted by the stimulus that consistently predicted reinforcement (the Allais paradox). When the probability of reinforcement associated with the discriminative stimulus that predicted reinforcement was reduced from 100% to 80% the pigeons still showed a strong preference for the discriminative stimulus alternative. Thus, under these conditions, the Allais paradox cannot account for the sub-optimal choice behavior shown by pigeons. Instead we propose that sub-optimal choice results from positive contrast between the low expectation of reinforcement associated with the discriminative stimulus alternative and the much higher obtained reinforcement when the stimulus associated with reinforcement appears. We propose that similar processes can account for sub-optimal gambling behavior by humans.