The state of ESG implementation among listed companies in Southeast Asia during 2015 - 2024: Improvement trends and divergence

This study examines the implementation of environmental, social, and governance (ESG) practices among 901 listed companies in Indonesia, Malaysia, the Philippines, Singapore, and Thailand during the 2015 - 2024 period. The study compares the full sample with a balanced group of 170 companies for which complete data are available over the entire ten-year period in order to isolate the effects of changes in sample composition. The results show that the average ESG score of the full sample declined after 2019; however, this decline was attributable to the expansion of the sample to include newly rated companies with relatively low initial scores. In contrast, the average ESG score of the balanced group increased continuously from 41.33 to 62.16 points. Thailand recorded the highest ESG scores, while Singapore and the Philippines showed the greatest improvements in the full sample. Malaysia exhibited the most pronounced divergence between long-established listed companies and newly rated companies. Formal governance mechanisms dedicated to ESG remain relatively uncommon. Based on these findings, the study provides implications for companies, investors, and regulatory authorities.