The assurance providers’ role in improving the independent assurance statement quality on sustainability reporting

Purpose This study aims to investigate the effect of assurance provider types on the independent assurance statement quality of Asian companies' sustainability report (SR) and examine environmental risk’s role as a moderating variable. Design/methodology/approach This study analyzes large Asian companies' stand-alone SR using moderated regression analysis to test hypotheses. Textual analysis is conducted to identify environmental risk disclosures. Findings This study shows that accounting assurance providers affect independent assurance statement quality in terms of compliance with assurance statement elements, while nonaccounting assurance providers can better accommodate environmental risk information required by the intended users. Research limitations/implications This study has several limitations. The research focuses on assurance statements and stand-alone SR of large companies in Asia; therefore, future research could examine similar analyses using integrated reports from Asia to investigate whether the results will differ. Additionally, this study does not divide assurance providers into Big-N and non-Big-N; thereby, it can be extended in future research. Practical implications Assurance providers need to consider environmental risk as a critical issue for the intended users to issue a high-quality independent assurance statement. Social implications Assurance statements issued by assurance providers increase public confidence in the reliability of the information contained in the SR. Therefore, regulators are expected to immediately set mandatory standards for sustainability assurance practices. Originality/value This study proves that accounting assurance providers can improve assurance statement quality. The variable environmental risk is also proven to be a pure moderator in negatively interacting the effect of assurance provider types on independent assurance statement quality.