The study examined how green performance disclosure influences the firm value of Nigerian listed conglomerates. An ex-post facto research design was adopted to analyse historical data that could not be manipulated. The population comprised all six conglomerate firms listed on the Nigerian Exchange Group, and a census approach was used to include all firms in the sample. Secondary data were collected from the annual reports and sustainability reports of the firms between 2015 and 2024, and green performance disclosure was measured using a four-item index. The hypotheses were tested using a panel regression model with fixed effects, following confirmation from the Hausman test, while controlling for firm size and leverage. The findings indicated that green performance disclosure had a positive and statistically significant effect on firm value (β = 0.933, p = 0.003), suggesting that firms can enhance their market valuation through transparent environmental reporting. Accordingly, it was recommended that management teams of Nigerian listed conglomerates should strengthen and systematize their environmental reporting by providing both qualitative and quantitative information in sustainability and annual reports. This would enhance market perception, demonstrate accountability, and reinforce investor confidence in the firm’s long-term operational and environmental strategies.
Chekwube-Aziekwe et al. (2026) studied this question.