ESG disclosure and firm value: a holistic approach to sustainability regulations and GRI compliance

Purpose The purpose of this study is to investigate whether achieving comprehensive ESG disclosure enhances firm value in emerging markets and whether the valuation relevance of ESG disclosure depends on credibility mechanisms, including Global Reporting Initiative (GRI) compliance, disclosure maturity, regulatory strength, materiality, disclosure intensity and third-party assurance. Design/methodology/approach This study constructs a GRI-based ESG disclosure measure and applies a staggered difference-in-differences design centered on each firm’s first attainment of a comprehensive ESG disclosure threshold from 2011 to 2021 in BRICS economies. This study also analyzes the role of GRI alignment and maturity, regulatory strength, disclosure intensity, materiality processes and third-party assurance. Findings The findings of this study suggest that firms reaching a comprehensive ESG disclosure threshold exhibit higher firm value in the post-adoption period. The valuation relevance of ESG disclosure is not uniform and becomes stronger when disclosure is more credible and comparable, particularly when aligned with GRI standards (and more mature GRI iterations) and when supported by stricter sustainability regulations, explicit materiality processes and external assurance. Practical implications Managers should focus on credible, decision-useful ESG reporting with aligned disclosure, clear materiality and assurance, rather than expanding the narrative alone. Investors should distinguish between the extent of disclosure and its credibility, and regulators can enhance market usefulness by integrating disclosure requirements with a credibility infrastructure. Social implications This study highlights the importance of robust regulatory frameworks and comprehensive ESG disclosure, which fosters corporate transparency and accountability. These efforts can yield broader societal benefits, including improved environmental sustainability and enhanced social well-being. Originality/value This study contributes by replacing third-party ESG ratings with a transparent, GRI-based comprehensive disclosure index and combining it with a staggered difference-in-difference threshold-attainment design to connect disclosure improvements to firm value. This study also demonstrates that valuation gains rely on credibility mechanisms (GRI maturity, materiality, assurance and regulatory strength) in emerging markets.