- 學位論文
企業購併成敗與股價變化的關聯性研究—以台灣上市（櫃）企業為例
To investigate the relationship between M&A and stock prices-The perspective of Taiwan listed companies
摘要
近十年企業購併在台灣成為非常熱門的話題。由於台灣的企業正面臨產業結構與經營型態的調整時期，使得公司藉由購併手段以進行多角化發展蔚為風潮。 本研究採用事件研究法中之市場模式來計算異常報酬，以採討企業購併事件的發生前後，其股價變化與購併事件的關聯性，以台灣證券交易所上市(櫃)公司，且曾經由工商時報、經濟日報或專業財經網站所揭露的購併事件之企業為樣本，抽樣期間自民國88年7月至91年3月。 本研究結果獲得之結論如下： 一、購併宣告事件日之股價走勢 1. 在購併宣告事件日之當天，購併成功的公司對股票價格具有資訊效果，而購併失敗的公司對股票價格並不具顯著之資訊效果。 2. 就購併宣告事件日的前後一段期間而言，(-5,+5)、(-10,+10)或(-22,+22)，顯示無論成功或失敗的公司，在購併宣告事件日的一段期間對股票價格並不具顯著之資訊效果。 二、購併結果確定日之股價走勢 1. 在購併結果確定日之當天，購併成功的公司對股票價格具顯著資訊效果，而購併失敗的公司對股票價格並不具顯著的資訊效果。 2. 就購併結果確定日之前後一段期間而言，(-5,+5)、(-10,+10)或(-22,+22)，購併成功的公司在(-22,+22)的確定期間具有負的顯著累積異常報酬，其原因可能為購併成功後，新公司在內部整合上並未比預期好，甚至更糟，投資人擔心股票價值降低，因此出售股票，導致股價下降；而購併失敗的公司在事件日期間並無顯著的累積異常報酬。
並列摘要
For the past decade, the operations of the M&A became the popular subject in Taiwan. Because enterprises have been facing against the transformed period of industrial structure and operational procedure, the enterprises diversify their products by M&A became a trend. This study uses market model of event study to calculate the abnormal return. The purpose is to investigate the relationship between the stock prices before the announcements and after the announcements of the M&A. The samples we used were obtained from the Taiwan Economic Journal 、 Commercial Times、Economic Daily News and economic websites. The study periods were adopted from July 1999 to March 2002. The conclusion of this study are as follows: A. Regarding the stock price on the announcement day of the M&A: (a) On the event day of M&A’s announcement, the successful merging companies have signaling effects on their stock prices. However, the failing companies do not have significantly signal effect. (b) During the period of the event day of M&A announcement, from -5 to +5、from -10 to +10 or from -22 to +22, the results did not demonstrate any signaling effect on the stock prices in both the successful and failed cases. B. Regarding the stock prices on the decision day of M&A: (a) On the decision day of M&A, the successful merging companies have positively signaling effects on their stock prices. However, the failed companies do not have any signaling effects. (b) During the decision period of M&A , from -5 to +5、from -10 to +10 or from -22 to +22, the successful merging companies have negative significantly cumulative abnormal return during the period of 22 days before M&A and 22 days after M&A. The reason might be the successful merging companies had some problems in internal integration. Many stockholders worried about the future of the new companies and sold out their stocks consequently, their stock prices drop down dramatically. However, the result indicated that the failed companies did not have any significantly abnormal return.