永續報告書之特性與ESG績效之關聯

Abstract

永續報告書是企業揭露ESG（環境、社會、公司治理）績效的重要工具，其內容涵蓋定量指標與敘述文字，後者允許企業透過語調等語言策略傳達資訊並形塑形象。然而，相較於財務報告語調影響投資人已有大量研究，永續報告的語調及異常語調的研究仍相對有限。過去ESG揭露文獻著重揭露程度與品質，較少探討「如何揭露」。因此，本研究聚焦永續報告書發布與否、第三方確信、文字語調及異常語調四構面，探討其與臺灣公司ESG績效的關聯。 本研究以2021–2023年臺灣企業為樣本，分析永續報告書文本內容，以正負字數比值衡量語調，異常語調則以語調偏離企業特徵預期值衡量，並以各公司ESG評等分數作為ESG績效之代理變數。透過多元迴歸檢驗報告揭露、第三方確信、語調正向程度與異常語調對ESG績效的影響，控制公司規模、財務績效等變數。 實證結果顯示，發布永續報告書的公司ESG分數顯著高於未發布者；報告經第三方確信亦與ESG分數顯著正相關。此外，語調愈正向，ESG評等愈高，尤以社會與治理構面受影響較大。異常樂觀語調同樣與ESG評等呈正相關，意即企業透過超出預期的語氣可提高外界對永續表現的評價。上述發現填補永續報告語調與ESG績效關係之研究缺口，亦凸顯非財務資訊溝通方式對ESG評價的重要性。

Sustainability reports serve as key instruments for companies to communicate their ESG (Environmental, Social, and Governance) performance, which include both quantitative data and narrative descriptions. While prior studies have explored tone in financial disclosures, little is known about the relationship between tone / abnormal tone and ESG performance. This study investigates the effects of report disclosure, third-party assurance, tone, and abnormal tone on ESG scores, which are proxies of ESG performance, among Taiwanese companies from 2021 to 2023. Empirical results reveal that firms disclosing sustainability reports and those obtaining third-party assurance receive significantly higher ESG scores. Moreover, reports with more positive tone are associated with better ESG ratings, particularly in the social and governance dimensions. Abnormal positive tone also correlates positively with ESG scores, suggesting that excessive positivity can enhance external perception of sustainability performance. These findings highlight the importance of not just what is disclosed, but how it is communicated, and underscore the need for ESG rating agencies to account for linguistic strategies and assurance quality in their assessments.