The Coexistence of Overestimation and Underweighting of Rare Events and the Contingent Recency Effect

Greg Barron ； Eldad Yechiam

《Judgment and Decision Making》 4卷6期 (2009/10) Pp. 447-460

並列摘要

Previous research demonstrates overestimation of rare events in judgment tasks, and underweighting of rare events in decisions from experience. The current paper presents three laboratory experiments and a field study that explore this pattern. The results suggest that the overestimation and underweighting pattern can emerge in parallel. Part of the difference between the two tendencies can be explained as a product of a contingent recency effect: Although the estimations reflect negative recency, choice behavior reflects positive recency. A similar pattern is observed in the field study: Immediately following an aversive rare-event (i.e., a suicide bombing) people believe the risk decreases (negative recency) but at the same time exhibit more cautious behavior (positive recency). The rest of the difference is consistent with two well established mechanisms: judgment error and the use of small samples in choice. Implications for the two-stage choice model are discussed.

並列關鍵字

decision making ； rare events ； judgment ； choice ； learning ； terror ； probability