A study of expert overconfidence

Overconfidence is one of the most common (and potentially severe) problems in expert judgment. To assess the extent of expert overconfidence, we analyzed a large data set on expert opinion compiled by Cooke and colleagues at the Technical University of Delft and elsewhere. This data set contains roughly five thousand 90% confidence intervals of uncertain quantities for which the true values are now known. Our analysis assesses the overall extent of overconfidence in the data set. Significant differences in the extent of overconfidence were found among studies, among experts, and among questions within a study. Moreover, replications (multiple realizations for the same question) allowed a preliminary assessment of whether the question effect is due largely to question difficulty, or merely to random noise in the realizations of the uncertain quantities. The results of this analysis suggest that much of the apparent question effect may be due to noise rather than systematic differences in the difficulty of achieving good calibration for different questions. The results support the differential weighting of experts, since there are significant differences in expert calibration within studies.     

考虑需求中断和购买者过度自信的应急物资动员链协调

以需求中断为背景,考虑常规采购和紧急采购,运用数量弹性契约构建了包含一个过度自信购买者(政府机构)和一个动员供应企业的应急物资动员链模型,得出了不同情境下的协调机制,探讨了紧急采购单价、契约参数、过度自信水平等因素对政府最优订货决策的影响。最后,结合汶川地震救灾帐篷动员背景进行算例分析。结果表明：当需求中断时,适当调整常规、紧急采购单价和契约参数能够协调应急物资动员链。当购买者为过度自信时,紧急采购调整单价高于非过度自信的情况;而供应企业会设置更低的常规采购单价以协调动员链。另外,过度自信会对应急物资动员链的最优订货量和整体期望利润产生负面影响。     

A randomized controlled evaluation study of the effects of a one-day advanced rider training course

Motorcyclists have a relative high risk of crash involvement. As a consequence there is an on-going search for safety measures to improve road safety for motorcyclists. One popular measure is motorcycle training. Although intuitively sound, there are only few thorough studies on rider training courses and they do not always show a positive safety effect.     

Why drivers use cell phones and support legislation to restrict this practice

The use of cell phones while driving is ubiquitous, particularly in countries where the practice is legal. However, surveys indicate that most drivers favor legislation to limit the use of mobile devices during the operation of a vehicle. A study was conducted to understand this inconsistency between what drivers do and what they advocate for others. Participants completed a survey about their driving attitudes, abilities, and behaviors. Following previous research, drivers reported using cell phones for benefits such as getting work done. The hypocrisy of using cell phones while advocating restrictions appears to stem from differences in the perceived safety risks of self vs. others’ use of cell phones. Many if not most drivers believe they can drive safely while using mobile devices. However, they lack confidence in others’ ability to drive safely while distracted and believe that others’ use of cell phones is dangerous. The threat to public safety of others’ usage of mobile devices was one of the strongest independent predictors of support for legislation to restrict cell phone use.     

Self-efficacy,overconfidence, and the negative effect on subsequent performance: A field study

Self-efficacy has been used to predict the level of performance or usage of IT. The psychological literature has suggested, however, that rather than promoting behavior, it can lead to overconfidence and reduce performance over time. We investigated this claim by studying the relationship between self-efficacy and performance in a field study. Overconfidence was measured metacognitively as the difference between a person's expected performance and his or her actual performance. Using PLS and a sample of 108 students in an systems analysis and design course, we found that for the sample as a whole, self-efficacy was positively and significantly related to performance, and that performance was positively and significantly related to subsequent self-efficacy. When levels of over- and under-confidence were taken into account, however, the relationships changed. In particular, overconfidence leads to a significant negative relationship between self-efficacy and subsequent performance. Implications for user training included the need to use performance feedback in order to allow for a recalibration of self-efficacy towards a more accurate self-assessment of ability.     

Implications of the research on expert overconfidence and dependence

In cases where interval estimates are obtained from expert opinion, the literature on expert overconfidence and dependence suggests that caution is in order. In particular, it may be inadvisable in such cases to interpret any areas of overlap among the intervals provided by the various experts as strong evidence that the quantity of interest falls within the region of overlap. The available literature on methods for assessing and compensating for overconfidence and for combining intervals or probability distributions from multiple experts is discussed. An ad hoc method of combining multiple expert opinions, suitable for use in relatively small projects, is also presented.     

基于过度自信的资本市场多期最优激励契约研究

在考虑经纪人过度自信变化的基础上，研究投资者与经纪人之间的多期激励契约．从行为金融学角度，建立经纪人过度自信的动态模型并指出其变化规律．应用委托-代理理论推导出资本市场的最优激励契约．分析经纪人过度自信及交易次数对最优激励契约的影响，给出了在无法观测到经纪人过度自信程度的条件下．投资者实际提供的契约与最优激励契约间的变化关系．