Determinants of ESG disclosure among listed firms under voluntary and mandatory ESG disclosure regimes in Hong Kong

Purpose The authors examine the determinants of ESG disclosure and differentiate between voluntary and mandatory disclosure regimes in Hong Kong. Design/methodology/approach The authors analyse both Bloomberg ESG scores and a disclosure index score, manually constructed according to the 2019 Hong Kong Exchange ESG Guide using regression tests. Findings The results indicate that the level of concentrated ownership is negatively associated with the quantity of ESG disclosure only in the voluntary disclosure period, suggesting that agency problems are alleviated when ESG reporting is mandatory. The findings also show that larger firms significantly disclose higher levels of ESG information in both voluntary and mandatory disclosure periods. Furthermore, the extent of ESG disclosure significantly increases when firms' sustainability reports are audited by Big 4 accounting firms only in the voluntary disclosure period. Finally, the control variables are significantly related to the level of ESG disclosure showing that ESG disclosure increased over time and is significantly different among industries. Originality The authors make contributions to the literature on non-financial disclosure in relation to ESG reporting by examining the relationship between firm characteristics and ESG disclosure in the Hong Kong context under both voluntary and mandatory disclosure regimes. This study also provides important implications for other stock markets and relevant stakeholders including preparers, users and the sustainability profession.