As a result, in 1999, Thai listed companies were asked by the SET to promote and build certain corporate governance practices into their annual reports (Ratanajongkol, et al., 2006).
These practices involved including both financial and non-financial information (economic,
social and environmental disclosures) in corporate annual reports, but disclosure was
voluntary so few listed companies revealed social and environmental information in their
annual reports. A revised version of the principle of good corporate governance was
published in 2006 (Lint, 2009) which suggested that boards of directors should set clear
policy on social and environmental issues and that companies should disclose social and
environmental policies as well as implementing the conditions of such policies. In addition,
voluntary reporting was changed to a “comply or explain” approach. The new principle has
been in force for Thai listed companies since 2007. However, the extent of TBL reporting by
companies in Thailand is still unknown.