Current decision-making models assume that an individual's attitude towards risk is unique. Hence, a decision maker's processing of probabilities and the resulting degree of probability weighting should not vary within the domain of risk. This paper provides evidence that challenges this assumption. We conduct two experiments involving different gambles, that is, risky games where objective probabilities are known, no further information-based advantages exist, and outcomes are independent of knowledge. Even though all probabilities are explicitly provided, we find that individuals exhibit more pronounced inverse-S-shaped probability weighting if they perceive their level of expertise regarding a gamble to be lower. This result suggests that individuals are subject to ignorance illusion in decisions under risk, constituting expertise-dependent risk attitudes. We document that ignorance illusion stems from the wrongly assigned importance of perceived expertise in the decision-making process and that it occurs in both the gain and the loss domain.

中文翻译：

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风险决策中的无知错觉：感知专业知识对概率加权的影响

当前的决策模型假设个人对风险的态度是独一无二的。因此，决策者对概率的处理以及由此产生的概率加权程度不应在风险域内变化。本文提供了挑战这一假设的证据。我们进行了两个涉及不同博弈的实验，即客观概率已知、不存在进一步的基于信息的优势且结果独立于知识的风险博弈。即使明确提供了所有概率，我们发现如果个人认为他们对赌博的专业水平较低，他们会表现出更明显的反 S 形概率权重。这一结果表明，个人在风险决策中容易受到无知错觉的影响，构成依赖于专业知识的风险态度。我们记录了无知错觉源于在决策过程中错误地分配了感知专业知识的重要性，并且它发生在收益和损失领域。