摘要：改善治理大环境，实现社保基金资产的安全增值一直是我国社会保障体系建设的核心。行业共同持股是社保基金作为特殊的机构投资者发挥对上市公司的治理作用的关键因素。本文选取2008—2019年中国A股上市公司为样本，研究发现，社保基金管理人行业共同持股能显著提升企业财务报告质量，发挥对上市公司的监督治理作用。在缓解了社保基金管理人行业共同持股与财务报告质量间关系的内生性问题后，结论依然成立。此外还发现，社保基金管理人行业共同持股的治理作用在非国有控股、内部治理较差、高管薪酬敏感性较高的企业中更为显著。机制检验表明，社保基金管理人行业共同持股作为市场的“风向标”，能通过吸引更多分析师关注，促进财务报告质量的提高。进一步研究发现，社保基金管理人行业共同持股具有协作效应和规模效应。考虑社保基金管理人其他投资策略的影响，发现社保基金管理人的投资规模和稳定性均与财务报告质量正相关。本文为社保基金管理人行业共同持股的监督治理效应提供了新的证据，也为监管部门实施更符合国情的措施以优化社保基金投资策略提供了参考。

Abstract: Improving the governance environment and realizing the safe appreciation of Social Security Fund (SSF) assets is always the core of the construction of social security system in China. Common ownership is the key factor for SSF to play its governance role in listed companies as a special institutional investor. Using the data set of listed companies from2008 to 2019 in China,this research examines that SSF manager's common ownership can significantly improve the quality of listed companies' financial reports quality. After relieving the endogenous problem of the relationship between the SSF manager's common ownership and the financial report quality,the resultis still robust. We further find that the governance effect of the SSF managers'common ownership is more significant in companies that are not state-owned, have poor internal governance, and have high CEO pay-performance sensitivity. Further study on the implication mechanism shows that, as the“weathervane”of themarket, SSF managers' common ownership can promote the financial reports quality by attracting more analysts' attention. Moreover, the SSF manager's common ownership has synergy effect and economy of scale. The larger investment scale and the higher stability of SSF managers' ownership, the stronger supervisory role ofthe SSF manager. This research gives new evidence for the supervision and governance effect of SSF managers'common ownership, and also provides a reference for the regulatory authorities to implement policy to optimize the investment strategy of SSF.