大型海外企業併購對集團企業股價之影響──台灣鴻海併購日本夏普之實證

The Impact of Conglomerate's Mega Overseas Mergers and Acquisitions on Affiliates' Stock Market Performance - Event Study on Taiwan's Japanese Foxconn-Sharp

本研究透過事件研究法，以臺灣鴻海集團併購日本夏普之個案來探討大型海外企業併購（Mergers and Acquisition, M&A）是否會造成其集團關係企業（概念股）股價異常報酬以及是否存在消息提前揭漏之現象。檢定結果指出，在事件日後的第一日及第二日以及事件日前的第三日及第四日出現顯著的正向異常報酬，此外，在事件日當天及事件日後的第四日與第五日皆出現顯著的負向異常報酬。類似的負向異常報酬也出現在事件日前的第二日、第五日至第七日與第十日。此研究結果顯示，相關股票投資者對此大型國際併購案的經營前景非常不確定，導致事件期間經常出現股價波動，這可能是由於投資者擔心雙方管理文化的融合與日本固有的“Datsuaron”自尊心的潛在衝突。此外，在我們的研究結果中，無法證明消息洩漏之合理性。

This study examines Taiwan's Japanese Foxconn-Sharpe case to explore whether a conglomerate's mega overseas merger and acquisition (M&A) will result in significant abnormal rates of return of its listed affiliates by event study methods. We also further explore whether there exist information leakage phenomena in this event. Our empirical results show that positive abnormal returns were found significantly on the first and second days after the event day and the third and fourth days before the event day. In addition, significant negative abnormal returns were evidenced on the event day as well as the fourth and fifth days thereafter. Similar abnormal negative returns also showed up on five days in the event period prior to the event day. The findings reveal that the related stock investors were so uncertain about the operation prospect of this mega international M&A that frequent significant stock price volatility was exhibited in the event period. This might result from investors' worry about the potential confliction of bilateral management culture fusion and Japanese inherent ''Datsuaron'' self-esteem. Moreover, information leakage cannot be significantly justified in our research findings.