近年來由於全球化趨勢,市場競爭程度更趨激烈,併購便成為一個重要的研究議題,國內企業所進行的併購事件,也往往受到市場矚目。本研究針對以台灣為主併者的全球併購,在國內股市所發生的累積平均異常報酬進行分析,並探討其可能的影響因素,藉此對照過去國內外相關的研究結果。 本研究資料來源有二。併購案件的資料是由SDC資料庫中所取得,樣本為台灣籍的主併公司,且在台灣股市有公開發行者;樣本取樣時間自1990年1月1日到2009年12月31日,每日股價及各公司市值資料,則由Datastream資料庫取得,扣除併購案未完成以及估計期與事件期重疊之併購案後,共有293筆資料,資料的處理及計算主要由MatLab、Excel以及SPSS進行。 本研究使用事件研究法,用以計算累積平均異常報酬,針對累積平均異常報酬的影響因素,則採取t檢定、變異數分析,以及迴歸分析等統計方法。 本研究結果顯示,此293筆併購案中的主併者,累積平均異常報酬在併購宣告的前三日到後三日達到高峰,但是沒有達到統計上的顯著水準,此點與過去的研究有些不同。本研究另外提出七個可能的影響因素,分別為:多角化程度、時間區塊、區域配對、標的公司態度、相對大小、交易方式,以及標的公司型態。本研究發現,當標的公司態度為不可行,以及相對大小較小時,存在較高的累積平均異常報酬,但並未達到統計上的顯著水準,而其餘影響因素皆無顯著的結果。 不顯著的結果可能由於台灣股市近年來受到政治因素等影響,或者是股市結構與歐美較為不同所致。另外,在影響因素的選擇上,本研究主要是使用量化變數,而許多質性的變數則未納入考量,如以併購的動機來衡量併購後的實際績效影響,則可能會提高模型的顯著程度。本研究在進行事件研究法的過程中,也存在若干盲點,無法完全釐清在估計期這段時間中樣本公司是否有其他事件發生,如發放股利、宣告重大決策、政經新聞等等,造成衡量異常報酬時可能受到影響。
Mergers and acquisitions (M&A) has become a significant research subject in recent years. The M&A cases of Taiwanese companies have received an increased attention from both the business and academic societies. Our research focused on the M&A cases with Taiwan acquirers, to investigate their cumulative average abnormal returns (CAR) during the M&A event windows. This study also tried to identify the possible determinants that influence the CAR. The M&A cases were collected from SDC database with the sampling period ranging from 1/1/1990 to 12/31/2009. The research samples are the companies publicly listed in the Taiwan stock exchange market and acted as the acquirers in the global M&A cases during the sampling period. The data regarding the stock price and market value are collected from the Datastream database. The final data used in the research include 293 cases. The event study method was used to calculate the CAR, while t-tests and ANOVA were used to identify how possible determinants influencing the CAR respectively. The research findings show insignificant CAR although there is a higher CAR(-3,+3) and CAR(-3,+1). With respect to the determinants (diversification, time period, region match, attitude of the target company, relative size, payment method and target public status), the research findings show that all factors have insignificant effects on the CAR. The insignificant results possibly result from the limited information collected by this study. For instance, the announcement of other events that might influence the market value and stock prices of companies, such as the dividend policy announcement which would affect the stock price during the estimation period and event period.