中華航空、復興航空這兩家國內著名的上市航空公司，根據重大事件紀錄，該二家航空公司於近年皆發生重大的飛航傷亡事件，不僅造成國民對飛行安全的恐慌，亦因鉅額賠償問題造成航空公司的財務危機，進而對二家航空公司之股價造成嚴重的衝擊。本研究主要目的即在探討當航空意外發生時，事件衝擊對公司股價造成的影響。藉由事件研究法，本文除了探討事件如何對股價產生衝擊，同時亦探討股價是否有過度反應（Overreaction）的現象？股價需經過多久才會進行修正？藉此做為判斷臺灣股市的效率性。 本研究採用11個國內外重要航空意外事件為樣，實證結果發現，重大事件日當天確實會對該公司股價造成異常變動，且以國內及影響全球經濟之事件更甚顯著，顯示股票市場一接受到重大訊息便會立即反應，造成標的股票股價出現負的異常報酬。另外，標的股價之異常報酬大多在事件當天以及之後一兩天隨即修正，顯示臺灣股票市場為半強式效率市場。 China Airlines and TransAsia Airways which are two well-known airline companies in Taiwan have suffered serious air crises in last decade. The air crisis not only makes passengers feel panic on flight, it also increases the risk of financial collapse due to the huge compensation. Therefore, it usually seriously negatively impacts to the equity price of the airline company. Using the event study method, this study aims for the purpose of examining how does it impact on the equity price? Does the equity price overreact to the air crisis event? How long does the impact will be prolonged? The empirical result can be the evidence for investigating the market efficiency of Taiwan. Using of a sample of 11 major air crisis which not only includes Taiwan air crisis but also considers the impact of international air crisis, we find that air crisis strongly negatively impact on the stock price & the stock price corrected immediately after 1-2 days. The result provides evidence to supports Taiwan's stock market is a semi-strong efficiency market.
