Sustainability Reporting and Firm Value: Evidence from Listed Firms in Nigeria, An Empirical Investigation Using Tobin's Q (2010–2024)

This study investigates the effect of sustainability reporting—operationalized through environmental, social, and governance (ESG) metrics—on firm value (Tobin's Q) of listed firms in Nigeria over the period 2010–2024. Employing an ex-post facto research design and panel regression methodology on a sample of 148 listed firms drawn from the Nigerian Exchange Group (NGX), the study controls for firm size, profitability, leverage, growth opportunities, firm age, and liquidity. Drawing on stakeholder theory, legitimacy theory, and the resource-based view, the findings reveal that ESG disclosure significantly and positively influences firm value, with governance disclosure exerting the strongest individual effect. Environmental and social disclosures also demonstrate positive but heterogeneous effects across industries. The study contributes novel empirical evidence from a frontier African market context, addressing critical gaps in the extant literature. Practical implications are drawn for regulators, corporate boards, investors, and policymakers seeking to mainstream sustainability in Nigeria's capital market ecosystem.