中文摘要：

消费者购买决策，特别是IT产品的购买决策中，从众现象非常普遍。然而，人们对隐藏在从众背后的作用机制却并不十分清楚。软件作为一种典型的IT产品，一般用户由于不具备丰富的产品知识，无法对它的价值独立作出正确的评估，因此，软件选择中的从众问题极其典型。对“压缩解压”和“闹铃时钟”两类软件的实证研究发现，在软件下载选择中，明显存在口碑效应、跟随效应、网络效应三种从众机制。口碑效应对从众的作用在两类软件中都是最大的，表明用户普遍容易受他人意见的影响，而跟随效应和网络效应的作用大小与产品功能特性有关：存在共享兼容问题的“压缩解压”软件网络效应更显著，表明用户倾向于选择已有用户人数较多的高共享价值软件；而个人独立使用的“闹铃时钟”软件则跟随效应更显著，表明用户更倾向于选择时尚的流行软件。

英文摘要：

Herding is common in consumers in terms of decision making ,especially when they are purchasing IT products. However, we are rarely aware of the behavior mechanics underlying herding phenomenon. Software product is a typical kind of IT products. Unfortunately, most users cannot make accurate assessment to the value of software independently due to insufficient knowledge of product information. In such case, herd behavior becomes quite typical in software adoption. In order to further explore the herding puzzle in software adoption, we develop a linear model which is based on Multinomial Logit Market-share model （MNL）, and which could effectively describe the three herding effects-network effect, information cascade effect and word- of-mouth effect. We have tested the linear model using the panel data from two different software called ＂Compress/Uncompress Tool＂ and ＂Alarm Clock＂ under Sina Software Download channel. Empirical results suggest： （1） Three herding mechanisms exist in software download choice-networkeffect, information cascade effect and word-of-mouth effect. ＂Recent Downloads,＂＂Total Downloads＂ and ＂User Rate＂ could be the three variables that represent the cause of the three effects respectively. These three variables have significant positive correlation with the market share of either ＂Compress/Uncompress Tool＂ or ＂Alarm Clock,＂ statistically proving the effectiveness of the three mechanisms. Information cascade effect suggests that users tend to choose popular software product to keep up with fashion trends. Network effect suggests that users tend to choose widely used software product for increment of shared value. Word-of-mouth effect indicates that users are remarkably influenced by decisions of others to minimize cognitive and emotional conflicts because they believe what most people believe. （2） The rank of the importance of the three mechanisms differs in the two software products adoption. Compared with network effect and information cascade effe