摘要
本研究資料以2018、2019 及2020年公司治理評鑑結果排名前5％ 的上市公司進行事件研究。實證結果顯示，2018 及2019年評鑑結果排名在前5％ 的公司，在評鑑結果公布前、後並無顯著的累積異常報酬。而在2020年評鑑結果公布前開始有顯著為正的累積異常報酬，並在結果公布後累積異常報酬反轉為負。結果顯示投資人在2020年以前並不重視公司治理評鑑的結果，而在2020年後開始將公司具有良好評鑑結果視為利多消息，並在消息公布前買進股票，在消息公布後進行獲利了結。
關鍵詞: 公司治理、事件研究、資訊揭露
Abstract
The data for this study are based on the listed companies ranked top 5% in the corporate governance evaluations in 2018, 2019 and 2020. The empirical results show that there were no significant cumulative abnormal returns around the date when the evaluations were announced for those companies in both 2018 and 2019. In 2020, however, the cumulative abnormal returns appeared to significantly positive before the announcement of the evaluation, while they became significantly negative after the announcement. The result shows that the ranking of the evaluation was not valued by investors before 2020 and that since then the high ranking has been regarded as positive information about the companies. They buy stocks before the positive information is announced and sell them out for profit after the positive information is announced.
Keywords: Corporate governance, Event study, Information disclosure