購併為公司重大投資決策，當企業購併宣告時，股價反應對經理人決策的看法，本研究收集1995年1月到2003年12月間台灣122家上市公司購併案為研究樣本，使用事件研究法估算宣告期間的異常報酬與累積異常報酬率，實證結果發現宣告日後一天異常報酬顯著為正；各事件窗口累積異常報酬亦顯著為正，且國際購併與相關購併的累積異常報酬亦顯著為正，顯示企業購併決策對於公司股價報酬有正面影響，投資人認同以購併以追求公司外部成長。並利用區別分析，將樣本公司依據公司治理變數加以區分累積異常報酬率的高低，實證發現公司治理機制對購併宣告股價報酬有影響，正確區別率高達86.11%。 Merger and acquisition are one of the most important investment decisions in corporate finance. When M&A is announced, investors evaluate the managers’ acquisition decisions are designed to enhance the wealth of shareholders or not. The study collected 122 M&A announcement of acquiring firms from January 1, 1995 to December 31, 2003. We employ event-study methodology to examine the abnormal returns and cumulative abnormal returns in event window. The empirical results found that the acquiring firms have positive abnormal returns on Day 1 and have positive CAR in different event window, both significant at the 1% level. International mergers and acquisition and mergers in related industry have significant short-term abnormal return. This results form this study shows us that stock price of acquiring firm have significantly AR & CAR during the period of the M&A announcement. It means that investors accept the idea that corporations use M&A to pursue the growth of the company. From the classification results from the discriminant analysis, there is 86.11% of grouped cases correctly classified. Corporate governance mechanism affects the stock returns in M&A announcements.
