Sustainability reporting assurance (SRA) ensures the credibility of sustainability information disclosed by companies. This practice has continued to evolve, particularly within regulatory frameworks. The SRA is widespread among the largest French and South African companies because of the requirements of GRENELLE II and KING III laws. The increased regulation of SRA and the increased rate of obtaining assurance motivated us to conduct our study. This study examines the impact of mandatory SRA on firm value. We run a fixed-effects ordinary least squares (OLS) panel model to test our hypothesis for the 2007–2018 period on a sample of 88 South African listed companies on the Johannesburg Stock Exchange (JSE) and 83 French listed companies on the SBF120 index. We use Tobin’s Q to measure firm value. Our results show a significant positive association between mandatory SRA and firm value. This finding implies that SRA regulations positively affect investors’ perceptions of firm performance, particularly firm value, for two reasons. First, mandatory SRA may strengthen firm legitimacy and establish a good reputation. Second, the adoption of SRA regulations plays an important role in reducing asymmetric information between various actors and solving agency problems between managers and shareholders. Regulators may be interested in the findings when considering current and future assurance requirements for sustainability reporting, and shareholders when considering SRA as an investment choice criterion.

可持续性报告保证 (SRA) 确保公司披露的可持续性信息的可信度。这种做法在不断发展，特别是在监管框架内。由于 GRENELLE II 和 KING III 法律的要求，SRA 在法国和南非最大的公司中很普遍。SRA 监管的加强和获得保证率的提高促使我们进行研究。本研究考察了强制性 SRA 对公司价值的影响。我们运行固定效应普通最小二乘法 (OLS) 面板模型来检验我们对 2007-2018 年期间的假设，样本为约翰内斯堡证券交易所 (JSE) 的 88 家南非上市公司和 SBF120 指数的 83 家法国上市公司. 我们使用 Tobin's Q 来衡量公司价值。我们的结果表明强制性 SRA 与公司价值之间存在显着的正相关关系。这一发现表明，SRA 法规对投资者对公司业绩（尤其是公司价值）的看法产生积极影响，原因有二。首先，强制性 SRA 可以增强公司的合法性并建立良好的声誉。其次，SRA 法规的采用对于减少各参与者之间的信息不对称和解决管理者与股东之间的代理问题具有重要作用。监管机构在考虑可持续性报告的当前和未来保证要求时可能会对调查结果感兴趣，而股东在将 SRA 视为投资选择标准时可能会对调查结果感兴趣。特别是公司价值，有两个原因。首先，强制性 SRA 可以增强公司的合法性并建立良好的声誉。其次，SRA 法规的采用对于减少各参与者之间的信息不对称和解决管理者与股东之间的代理问题具有重要作用。监管机构在考虑可持续性报告的当前和未来保证要求时可能会对调查结果感兴趣，而股东在将 SRA 视为投资选择标准时可能会对调查结果感兴趣。特别是公司价值，有两个原因。首先，强制性 SRA 可以增强公司的合法性并建立良好的声誉。其次，SRA 法规的采用对于减少各参与者之间的信息不对称和解决管理者与股东之间的代理问题具有重要作用。监管机构在考虑可持续性报告的当前和未来保证要求时可能会对调查结果感兴趣，而股东在将 SRA 视为投资选择标准时可能会对调查结果感兴趣。