Abstract: IT crowdsourcing market is an Internet-based IT outsourcing market. In this paper, taking the data of IT crowdsourcing service providers in 4 subcategories of IT services in crowdsourcing website as samples, the Pareto curve and panel data analysis were used to test the impact of the Internet information disclosure and the interactive effect of online reputation and self-presentation on the market concentration of IT crowdsourcing. The results show that there is a “star effect” in the IT crowdsourcing market under the information disclosure mechanism of the Internet, which is inefficient for the entire IT crowdsourcing market. The IT crowdsourcing market of an IT service providers with a high online reputation or a high self-presentation is less centralized than that of an IT service provider with a low online reputation or a low self-presentation. An effective way to reduce the concentration of the IT crowdsourcing market is to bring in enough IT crowdsourcing providers with high online reputations and high self-presentations, and improve the information disclosure mechanism of crowd-sourcing platform will help improve the efficiency of IT crowd-sourcing market.

Key words: market concentration, IT crowdsourcing, online reputation, online self-presentation, interaction effect

摘要： IT众包市场是互联网化的IT外包市场。以众包网站IT服务中4个细分市场的 IT众包服务提供商的数据为样本，运用帕累托曲线和面板数据分析检验了互联网的信息披露对IT众包市场集中度的影响，以及在线声誉和在线自我展示对于IT众包市场集中度的交互效应。研究结果表明：IT众包市场在互联网的信息披露机制下存在着“明星效应”，这对于整个IT 众包市场而言是低效率的；一个拥有较高在线声誉或较高在线自我展示的IT众包服务商的IT众包市场要比一个拥有较低在线声誉或较低在线自我展示的IT众包服务商的IT众包市场集中度更低；消减IT众包市场集中度的一个有效的方式就是加入足够多高在线声誉和高在线自我展示的IT众包服务提供商，完善众包平台的信息披露机制将有利于提高IT众包市场的效率。

关键词: 市场集中, IT众包, 在线声誉, 在线自我展示, 交互效应