已有研究发现，在投资者法律保护水平落后的国家，企业的股权结构高度集中，从而形成了非分散化投资的控股股东。本课题以我国非分散化投资的民营控股股东为切入点，分析其建立的企业集团是否存在保险效应（成员公司之间风险分担的行为），以及该保险效应对企业风险承受能力（risk-taking）的影响。具体拟回答几个问题：我国民营企业集团是否存在保险效应？该保险效应是否会因为外聘职业经理人的代理问题而减弱？企业集团的保险效应是否可以缓解困境成员公司的银行融资约束？是否可以帮助成员公司脱困？是否可以增强成员公司的风险承受能力？本课题在理论上一方面分析了控股股东利用企业集团保险效应以降低风险的动机，拓展了企业集团普遍存在的相关研究；另一方面从企业组织结构的视角拓展了企业风险承受能力的相关研究。本课题在实践中有助于为民营企业防范风险、提高风险承受能力提供理论指导，进而为促进我国民营部门和总体经济增长提供政策建议。

Prior researches find that companies in countries with poor investor protection have more concentrated ownership of their shares, which leads to the undiversified controlling shareholder. Based on the undiversified controlling shareholder, this project analyzes whether the mutual insurance exists in the private business groups, and the effects of the mutual insurance on the risk-taking of business group affiliation. We attempt to answer five questions. Does the mutual insurance exist in the private business groups? Will the mutual insurance be reduced by the professional managers for the agency problem? Can the mutual insurance mitigate the bank financing constraints of the business group affiliation in financial distress? Can the mutual insurance rescue the business group affiliation from financial distress? Can the mutual insurance increase the risk-taking of business group affiliation? On one hand, our project contributes to the extant research on the prevalence of business groups by analyzing the undiversified controlling shareholder's motivation to use the mutual insurance to reduce risk. On the other hand, our project contributes to the extant research on firm risk-taking by introducing business groups. In practice, our project provides guidance for the private firm's risk management, and suggestions for the growth of private sector and the economy of China.