中文摘要：

基于代理成本理论,诸多研究探讨了董事会特征、股权结构和债务杠杆等公司治理机制对上市公司多元化动因及绩效的影响,但鲜有研究关注多元化公司的审计师选择行为以及高质量审计对多元化公司代理成本和价值的影响。以2003-2011年A股上市公司为样本的研究发现,代理成本越高的多元化公司越可能选择高质量审计师,而高质量审计师确实能够降低多元化公司的代理成本并抑制多元化折价;进一步的检验还发现,相对于国有多元化公司,高质量审计可以更显著地提升非国有多元化公司的价值。

英文摘要：

Based on the agency cost theory, many studies have mechanisms such as characteristics of the board of directors, o investigated how internal governance wnership structure, etc. influence the company＇s diversification strategy and the diversification discount. However, few research focuses on the diversified company＇s behavior of auditor selection and the impact of high-quality audit on such company＇s agency cost and value. We find the diversified company with higher agency costs is more likely to choose high-quality auditors, and high-quality auditors can indeed reduce the diversified company＇s agency cost and control the diversification discount. Further test shows that compared with the state-owned diversified company, high-quality audit can more significantly improve the value of non-state-owned diversified company.