公司治理評鑑結果對股票異常報酬之影響

Abstract

本研究探討公司治理評鑑結果對股票異常報酬之影響，以2014 年至2020 年間臺灣上市櫃公司之公司治理評鑑結果A+及A為樣本。採用事件研究法之市場指數調整模式進行實證分析，檢視公司治理評鑑結果公布後股價表現影響，並進一步檢視不同種類公司的股價異常報酬之差異。實證結果顯示公司治理評鑑結果為A+及A的公司，在公布評鑑結果之後3個交易日股價呈現正向異常報酬，尤其對於營業利益率較高的公司、營收成長率較高的公司、本益比較高的公司，此正向異常報酬更為顯著。This study explores the effect of corporate governance evaluation results on abnormal returns of stocks, with A+ and A rated TWSE/TPEx listed companies in corporate governance evaluations from 2014 to 2020 as samples. An empirical analysis using event-based market adjusted return model was conducted to examine the impact of corporate governance evaluation results on stock price performance and further investigate distinct abnormal returns for different types of stocks. The empirical results showed that companies with A+ and A corporate governance evaluation ratings have positive abnormal returns for three trading days after the announcement of the evaluation results. For companieswith higher operating profit margins, higher revenue growth rates, and higher cost-to-benefit ratios, such positive abnormal returns are more significant.