信息瀑布中的动物精神

"Animal Spirits" in Information Cascade

信息瀑布行为已被研究者逐渐接受并作为经典金融市场理论的有力补充,但现有"一次决策"信息瀑布实验很难刻画这种信念依赖现象;赋予决策者对同一事件一次以上序贯选择机会的多决策信息瀑布实验更符合实际。结果表明:第二次决策阶段信息瀑布发生率显著提高,但决策正确率却有所下降,这为凯恩斯的"动物精神说"提供了实验证据。此外,平衡状态下位于决策序位中部的决策者系统性地背叛了自己的私人信息。

Information cascade challenging the EMH has been grad-ually accepted by researchers as a powerful complement to classic theory of the finance market.However,the existing experiments on information cascade are all one shot games which fail to describe this phenomenon of belief dependence.In contrast,the multi-shot game information cascade experiments better accord with the reality in which the decision makers are assigned more than one sequential choice opportunity toward one identical event.Multi-shot game information cascade experiments are designed initially in this paper,obtaining 2880 decision data.The results indicate：（1） compared with the first stage decision,the incidence of information cascade is increased during the second decision stage with no new information entering the market.This group accordance behavior that individual decision makers represent rule out the motivation of information acquisition,which is a kind of conformity preference and provide experimental evidence to Keynes＇ ＂Animal spirits theo-ry＂;（2） the individual decision-making accuracy in the second stage is lower than that in the first stage;（3） whether the decision-making accuracy or the incidence of information cascade is not affected by gender.The more rearward the decision-making sequence is,the more easily information cascade happens.But the accuracy is not increased.As the number of experiment period goes up,there is an obvious learning effect on individual decision-making accuracy;（5） by the analysis of individual behaviors under the balance state,we find that the individuals in the middle orders are inclined to ignore their private information.The decision makers in the eighth order in our multi-shot game information cascade experiments systematically deviate from their own private information.