| Abstract: | 本研究以中華航空與長榮航空公司為例，探討航空公司罷工訊息 (分別發生在2016年6月24日與2019年6月20日) ，對航空公司本身及其他相關產業 (運輸與觀光飯店類股) 的股價 (股票報酬) 之影響，並分析影響異常報酬率橫斷面變異的原因。使用傳統事件研究法和事件研究迴歸分析法，配合四因子定價模式之使用，研究結果彙整說明如下：一、航空公司罷工事件對其所有相關產業股價的影響，因罷工解決時間而有不同：中華航空事件日之後並無顯著異常報酬，可能與該次罷工在一天中快速落幕有關；而長榮航空罷工事件日到其後約兩日有負異常報酬，說明罷工對航空公司有極大的負面衝擊，導致企業市場價值嚴重減損。二、罷工事件對航空相關互惠企業股價產生的負異常報酬率因其事件發展而有差異：中華航空罷工事件日相關互惠企業股票在事件日和第一日有負異常報酬；長榮航空罷工並無此現象，可能是事件發展突然且不明朗，並有先前中華航空罷工順利解決的先例，使投資人或許認為罷工未必不好。三、樣本航空公司之競爭者股票皆在罷工事件日前一日有正異常報酬，至於其後之股價反應則因事件解決與否而有差異：競爭者在中華航空罷工事件日後第一日有顯著負異常報酬，應是該罷工事件處理相當迅速圓滿解決，如此反而對競爭者無好處。至於長榮航空罷工，事件當日競爭者股價有顯著正向反應，與直覺和預期一致。四、航空業之互惠性產業及競爭性產業股價受其資產規模、成長性、資產報酬率和獨立董監事比率的影響，且因罷工事件解決之時間長短與投資人想法而有差異，也隨互惠性或競爭性產業而有不同。
This study uses the China Airlines and the EVA Airways as examples to discuss the impact of airline strike messages (which occurred on June 24, 2016 and June 20, 2019, respectively) on stock price (returns) for airlines and other related industries (the transport and tourist hotel stocks) , and analyze the reasons for the cross-sectional variation of stock abnormal returns. Using traditional event study method and event-study regression analysis methods, applying the four-factor pricing model, the research’s results are summarized and explained as follows: 1. The impact of the strikes on the stock prices of the industries related to airlines differs according to the time it takes for the strike to be resolved: there is no significant abnormal returns after the China Airlines strike event date, which may be related to the rapid closure of the strike in one day. For the EVA Airways strike event date, about two days later, there was negative abnormal returns, indicating that the strike had a great negative impact on airlines, resulting in serious loss of market value of the enterprise. 2. The negative abnormal returns generated by the strike event on the stocks of airline-related reciprocal companies differs according to the development of the event: the stocks of the relevant reciprocal companies of the strike event of China Airlines has a negative abnormal return on the event day and the first day later. But the EVA Airways has not this phenomenon, may be due to the sudden and unclear development of the event, and there is a precedent for the successful resolution of the previous strike of China Airlines, so that investors may think that the strike is not necessarily bad.3. The competitors’ stocks of the sample airlines all have positive and abnormal returns on the day before the strike event, and the subsequent stock price reaction differs depending on whether the event is resolved or not: the competitors on the first day after the China Airlines strike event have significant negative abnormal returns, should be due to the fact that the strike is handled fairly quickly and satisfactorily, which would not be good to competitors. As for the EVA Airways strike, the competitor's stock price on the event day had a significant positive reaction, consistent with intuition and expectations. 4. The share prices of reciprocal and competitive industries in the aviation industry are affected by the size of their assets, growth, return on assets, and the ratio of independent directors and supervisors. Also, the length of time for the resolution of strikes, investors’ ideas, and reciprocity or competitive industries are the factors affecting stock prices. |
