得失程数的变化:损失规避现象的新视点

Is Loss Aversion A Robust Effect? An Uneven Route of Seeing that losses Loom Larger than the Same Amount of Gains

损失规避是预期理论的核心部分之一,指等量的损失和获得产生的心理效用并不相同,前者大于后者。大量研究从生理、认知、情感等角度探讨损失规避的内在机制和规律,以期认识、预测并控制损失规避导致的偏差。本研究假设损失规避与获得或损失的"程数"(route)有关,以往研究发现了损失规避现象,是由于其采用的"双程损失-单程获得"典型情境中,损失程数多于获得程数。为检验该假设,本研究设计了不同于传统范式的"获得和损失程数相等"的镜像情境、"单程损失-双程获得"及"三程获得"三种不同的得失情境。研究结果支持本假设:当损失的程数等于或少于获得的程数时,损失规避现象消失;获得或损失的程数越多,个体对其的心理感受强度趋于越高。建议未来研究进一步检验心理感受强度在程数和损失规避行为之间的中介作用。

Loss aversion,which means that negative changes （losses） loom larger than equivalent positive changes （gains）,is one of the basic elements of Prospect Theory. The general accepted interpretation for lose aversion is that the outcome of choice can be regarded as gains or losses compared with different reference points,and that losses have greater impact on preference than gains. In the present research,we hypothesized that the loss aversion was due to the uneven routes of gains and losses,where ＂route＂ was defined as the number of transitions of the same possession. In conventional scenarios,the gains were usually one-route with the one transition from not having a possession to having it,whereas the losses were typically two-route,with the another transition from having to not having it. As a result,the reason why lose aversion can be detected in these scenarios is because the number of routes for losses is greater than that for gains,and that the greater number of routes brings stronger psychological feelings. To test our hypothesis,several scenarios were developed which differed from the traditional one of ＂one-route gains vs. two-route losses＂. A total of 355 undergraduate or graduate students were recruited and paid for participation. In Study 1,＂one-route gains vs. one-route losses＂,＂two-route gains vs. one-route losses＂ and ＂one-route gains vs. three-route gains＂ scenarios were designed and posed to participants. The possible loss aversion was measured by the participants＇ willingness to accept symmetric fair bets and the ratio of loss to gain. In Study 2,the psychological feeling was measured by using unmarked lines and hand dynamometer to examine whether psychological feeling varied with the number of routes of losses and gains. The results revealed that：（1） the loss aversion effect was not robust enough to survive in a context where the asymmetry pattern of ＂one-route gain vs. two-route loss＂ was changed or reversed,and （2） the more routes of gains and losses were imposed,the stronger psychological feelings will be experienced. The present data pit route-based account against the reference point account and demonstrate that the mechanism of route may provide a more promising explanation for the observed changes in loss aversion. The implications of these findings for tax policy-making and social reform were discussed.