大型海外企業併購對股市之影響－台灣明基併購德國西門子之實證

本研究以事件研究法分析台灣明基併購德國西門子手機事業部門事件，探討資訊科技產業海外大型併購訊息，是否會造成其他資訊科技龍頭企業之股價異常報酬率；並進一步探討該事件是否存在訊息提前洩露的現象。本研究實證結果顯示，雖然事件日當天未具異常報酬率顯著性，但在事件日後的第一天和第三天以及事件日之前的事件期（十天）當中有五天皆確實出現正向的異常報酬率顯著性。此外，在事件日前的事件期間普遍呈現訊息提前洩露的顯著性，此現象應是媒體在官方正式併購訊息發布前即已廣泛的大幅報導所致。本研究從股票市場在事件期間的持續多頭加碼買進可以推理得知，相關資訊科技龍頭企業的股票投資人的確非常期待此廣受高度矚目的國際併購能產生「典範轉移」的正面效果。然而，事件期間時而出現的顯著股價回檔亦同時顯示出台灣投資人憂心雙方管理制度整合、德國強大工會，以及嚴格的勞工保護法規所可能帶來的潛在扞格，對於該大型併購案的營運前景充滿著懸念。

關鍵字

事件研究法；併購；異常報酬率；典範轉移

並列摘要

This study examines Taiwan's German BenQ-Simens case to explore whether the IT mega overseas merger and acquisition (M&A) will result in significant abnormal rates of return of other IT powerhouses by event study methods. We also further explore whether there exists information leakage phenomena in this event. Our empirical results show that even though abnormal return significance was not detected on the event day, positive significance yes indeed shows up on the first and third days thereafter as well as five days within the event period prior to the event day. Moreover, information leakage evidences were exhibited almost throughout the event period prior to the event day, and supposed to result from the earlier comprehensive media attention before the official news announcement. Our empirical evidences on abnormal return reveal that the related IT powerhouses' stock investors truly look forward to seeing the positive effect of ＂paradigm shift＂ through this high-profile international M&A, therefore taking continuously bullish actions. However, intermittent significant price drawdowns show that investors were so uncertain about the operation prospect of this mega M&A due to their worries about potential conflictions of bilateral management system integration and German mighty labor unions and strict labor protection law as well.