Mandatory versus voluntary: The real effect of ESG disclosures on corporate earnings management

• Mandatory ESG disclosure reduces firms' earnings management. • Voluntary ESG disclosure has almost no significant impact on earnings management. • Mandatory disclosure reduces information asymmetry by transparent accounting items. • The reduction effect is more pronounced for firms with high manipulation incentives. • Mandatory ESG disclosure improves ESG reporting quality and ESG performance of firms. This paper aims to explore the real effect of mandatory and voluntary environmental, social, and governance (ESG) disclosure on corporate earnings management. We find that mandatory ESG disclosure has a negative effect on firms’ earnings management, while voluntary disclosure has almost no significant impact. We exploit China’s 2008 mandate regulation and construct a difference-in-differences design to show that firms with mandatory ESG disclosure experience an alleviation of information asymmetry through increased transparency of specific accounting items and eventually decrease earnings management. In addition, the negative effect of mandatory ESG disclosure is more pronounced for firms with stronger motivations to manipulate earnings. We also find that the ESG disclosure quality is higher under mandatory disclosure and the environmental, social, and government performance is improved for firms disclosed ESG reports. Our results support the view that mandatory ESG disclosure has informative advantages over voluntary disclosure and improves the quality of financial reporting.