股價對環境、社會治理負面訊息反應之研究

Stock Price Reaction to Bad News of Environmental, Social and Governance Issues

本研究探討企業發生負面的社會責任事件時是否會影響投資人的決策，同時亦加以檢測ESG（環境、社會、治理）這三種社會責任因子對股價報酬的影響是否有程度上的差異。此外，本研究同時採用估計期150天及300天作為本研究的參數估計期，深入討論這兩種不同的參數估計期是否會產生不同的實證結果。研究結果顯示，當企業發生負面的ESG新聞事件時，的確會造成公司股價報酬下跌的結果。其中又以治理因子對股價報酬的影響最大，且治理事件較易有訊息事先走漏的情形。此外，不同的參數估計期間沒有顯著差異，亦即估計期的長短並不會造成ESG事件有顯著的不同結果。 The study investigated the impact of bad news in corporate social responsibility reporting on investors' decision making. We also examine and compare the degree of price reaction to the three social responsibility factors (environment, society and governance) used in this study. In addition, this paper designs two different estimated periods of 150 days and 300 days. This is to explore whether different parameter estimation periods will generate different empirical results. It concludes that the price premium will fall down significantly when negative ESG news is announced. The bad news of governance factor has the most impact on stock returns. The governance event is more easily leaking out in advance. Furthermore, different parameter estimation period will not yield different effect.