本研究針對企業社會責任報告書的編製原因、認證與否以及認證種類的不同,探討投資人在報告書發布前後的市場反應。研究結果顯示,企業社會責任報告書經認證的企業相較於非經認證的企業產生較高的股價異常報酬,而採用較可靠認證方法的企業相較於採用較不可靠認證或無認證的企業,雖產生較高的股價異常報酬,但未達顯著水準。此項研究結果證實,經認證的企業社會責任報告書可以提供更可靠資訊以及提升資訊的內涵價值,使投資人更樂於投資該企業。但可能因為並非所有投資人都了解不同認證種類的差異,採用較可靠認證企業最終未能展現顯著較高報酬。最後,本研究發現,自願編製或自願編製且通過較可靠認證的企業,其股價異常報酬並未明顯高於其他公司。
This study investigates stock price reaction to the issuance of corporate social responsibility (CSR) reports as it relates to whether the reports are mandated, receive assurance, and receive reliable assurance. The results of the study reveal that companies issuing assured CSR reports experience higher abnormal returns than non-assured companies. Meanwhile, companies adopting more reliable assurance methods experience higher returns than other companies, but the results are nonsignificant. The reported results suggest that assured CSR reports provide more reliable information and enhance the value of the information, which makes investors more willing to invest. On the other hand, companies whose reports receive more reliable assurance do not have significantly higher returns, which could be attributed to a lack of understanding of the different types of assurance methods on the part of many of the investors. Finally, this study finds that companies that voluntarily prepare CSR reports do not have significantly higher abnormal returns than others, which is the case even if they adopt more reliable assurance methods.