从众心理--羊群效应资料.ppt

Bandwagon effect 从众心理,1. Definition,2.Origin of the phrase,3.Use in politics,5.Use in microeconomics,4. Use in science,1.Definition 从众心理又叫羊群效应 Herd Instinct也称“跟风效应”，英文中将其描述为：The Greater-fool-Game，意为“下家都是比你更大的傻瓜” 羊群行为(Herding Behaviors)是一种特殊的非理性行为，是指投资者在信息环境不确定的情况下，行为受到其他投资者的影响，模仿他人决策，或者过度依赖于舆论(即市场中的压倒多数的观念)，而不考虑自己的信息的行为由于羊群行为涉及多个投资主体的相关性行为，对于市场的稳定性、效率有很大影响，也和金融危机有密切的关系，因此，羊群行为引起了学术界和政府监管部门的广泛关注1.Definition The bandwagon effect, also known as the “cromo effect“ and closely related to opportunism, is a phenomenon—observed primarily within the fields of microeconomics, political science, and behaviorism—that people often do and believe things merely because many other people do and believe the same things. The effect is often called herd instinct, though strictly speaking, this effect is not a result of herd instinct. The bandwagon effect is the reason for the bandwagon fallacy's success.,2. Origin of the phrase Literally, a bandwagon is a wagon which carries the band in a parade, circus or other entertainment.The phrase “jump on the bandwagon“ first appeared in American politics in 1848 when Dan Rice, a famous and popular circus clown of the time, used his bandwagon and its music to gain attention for his political campaign appearances. As his campaign became more successful, other politicians strove for a seat on the bandwagon, hoping to be associated with his success. Later, during the time of William Jennings Bryan's 1900 presidential campaign, bandwagons had become standard in campaigns,and “jump on the bandwagon“ was used as a derogatory term, implying that people were associating themselves with the success without considering what they associated themselves with.,乐队花车 从众效应又被称为「乐队花车效应」，也就是在花车大游行中搭载乐队的花车。

参加者只要跳上了这台乐队花车，就能够轻松地享受游行中的音乐，又不用走路，也因此，英文中的片语（跳上乐队花车）就代表了「进入主流」这片语首先在1848年的美国政府中，由林肯时代的一个小丑使用专业的马戏团小丑丹•赖斯，在为扎卡里•泰勒竞选宣传时，使用了乐队花车的音乐来吸引民众注目当泰勒的宣传日益成功时，越来越多政客为求利益而投向了泰勒1900年，威廉•詹宁斯•布莱恩参选美国总统选举时，乐队花车已成为竞选不可或缺的一部份3. Use in politics The bandwagon effect occurs in voting: some people vote for those candidates or parties who are likely to succeed (or are proclaimed as such by the media), hoping to be on the “winner's side“ in the end.The bandwagon effect has been applied to situations involving majority opinion, such as political outcomes, where people alter their opinions to the majority view (McAllister and Studlar 721). Such a shift in opinion can occur because individuals draw inferences from the decisions of others, as in an informational cascade. 选举中常见到的从众效应：一些选民会把选票投给那些很可能胜出（或在传媒中如此宣称）的候选人，从而增加他们真的胜出的机会。

4. Use in science 科学领域中，一些科学家因为研究结果异于主流思想，故把自己的研究成果隐藏例如，量度太阳与银河系中心的距离──一个天文学的重要数值时，纵然使用了不同的量度方法，但公布的结果往往与当时所接受的数值吻合若果量度结果与流行的数值相差甚远，科学家往往会反复检验自己的方法，重复计算的步骤，最终延后或放弃发表研究成果 若非从众效应，不同科学家所公布的估计应该先有天渊之别，然后因量度的精准度增加，估计数值才会趋向固定数值但现实中，发表的众多估计数值往往聚在一起，并随着时间走向同一个方向5. Use in microeconomics In microeconomics, bandwagon effect describes interactions of demand and preference.The bandwagon effect arises when people's preference for a commodity increases as the number of people buying it increases. This interaction potentially disturbs the normal results of the theory of supply and demand, which assumes that consumers make buying decisions solely based on price and their own personal preference. Gary Becker has even argued that the bandwagon effect could be so strong as to make the demand curve slope upward. This belies the fact that there is no empirical evidence for a bandwagon demand relationship with a positive coefficient. Others argue further that a positive coefficient is inconsistent with demand parameterizations and generates comparative static implications that are untenable. See network effect and Veblen good.,5. Use in microeconomics 在微观经济学里，从众效应影响需求和偏爱之间的互动。

受从众效应影响，当购买一件商品的人数增加，人们对它的偏爱也会增加这种关系会影响供求理论所解释的现象，因为供求理论假设消费者只会按照价格和自己的个人偏爱来买东西在证券交易市场中，从众效应可以使一支证券短时期内提升至一个不合理的水平股市中的羊群效应——急涨急跌,羊群效应是证券市场的怪现象,,,,,,,,,,,。