Robustness tests.

As an important part of improving the socialist market economic system, the social credit system focuses on the market’s micro behavior, which emphasizes the credit self-discipline of enterprises in financial management and checks the orientation for enterprises’ investment decisions. This study selected Shanghai and Shenzhen A-share listed companies for 2012–2023 as samples and used the pilot reform of China’s social credit system as a quasi-natural experiment to test the impact and mechanisms of the construction of the social credit system on enterprises’ overinvestment. The main findings show that the social credit system construction alleviates enterprises’ overinvestment behaviors, realized by the inhibiting effect of internal controls, the reverse effect of risk monitoring, and the guiding effect of business environment optimization. Heterogeneity analyses illustrate that the social credit system construction has a more obvious inhibitory effect on overinvestment for enterprises that are less subject to financing constraints, have higher internet penetration, have better financial development levels, are eastern, non-manufacturing, and large-scale. The conclusions provide new perspectives and references for the government and enterprises to re-examine the economic effects of the social credit system construction, which can promote capital usage efficiency and guide enterprises toward rational management.作为完善社会主义市场经济体制的重要组成部分，社会信用体系聚焦市场微观主体行为，强调企业在财务管理中的信用自律，并对企业投资决策方向形成约束。本研究以2012-2023年沪深A股上市公司为样本，以中国社会信用体系试点改革为准自然实验，检验社会信用体系建设对企业过度投资的影响及其作用机制。主要研究结果表明，社会信用体系建设能够缓解企业过度投资行为，具体通过内部控制的抑制效应、风险监控的反向调节效应以及营商环境优化的引导效应得以实现。异质性分析显示，社会信用体系建设对融资约束程度更低、所在地区互联网普及率更高、金融发展水平更佳、位于东部地区、非制造业以及大规模企业的过度投资行为具有更显著的抑制作用。本研究结论为政府与企业重新审视社会信用体系建设的经济效应提供了新视角与参考依据，有助于提升资本使用效率，引导企业开展理性经营活动。