The Announcement Effect Earnings Management and Post-Merger Performances of Merger and Acquisition

[[abstract]]本研究探討以股票交換的方式進行併購的公司，是否會從事盈餘管理來提升公司價值以降低併購成本，並檢視併購公司於併購宣告前進行盈餘管理的時點及併購前盈餘管理與併購事件日之相關性，最後探討併購後績效。 研究結果發現併購公司在宣告日當天有正向顯著的平均異常報酬率；併購公司於併購宣告日前兩季操弄盈餘，且股權交換盈餘操弄程度大於現金支付；在併購前盈餘管理程度與併購完成日股價報酬相關性呈負相關。併購後對主倂公司長期績效的影響，在風險方面，股票市場風險正向顯著、總風險呈負向顯著。在營運綜效方面，均於併購後呈現衰退現象，但若觀察調整產業後之併購績效，則各項比率檢定並無顯著，表示樣本公司在併購前後相較之下雖呈現較差表現，但相較於調整產業後之併購績效，主併公司在整個產業中並無較差的表現。 在併購前盈餘管理程度與併購完成後績效呈顯著負相關。在併購前盈餘管理程度與併購完成後之股價報酬關係，樣本公司調整前後報酬率皆與併購前盈餘管理與併購完成後一年股價報酬率之相關顯著為負，但與併購完成後二及三年股價報酬率之相關係數則不顯著，表示在併購後第一年盈餘管理之反轉效果已於股價中反應完畢，併購後之股票報酬則與併購前盈餘管理無關。[[abstract]]The study focuses on the merger and acquisition companies by stock swap's way discusses whether companies engage in the earnings management to promote the company value for reducing the merger and acquisition cost investigates companies announcing to prepare merger and acquisition whose correlation between pre-merger and acquisition of the earnings management and the merger and acquisition event date Finally the study discusses the Post-Merger Performances The results show that the merger and acquisition company had the remarkable mean anomaly return in the announcement date; the merger and acquisition company would manipulate the earnings management for two seasons before the announcement; the stockholder's rights exchange earnings manipulated more than the cash payment; the earnings management of the pre-merger and acquisition and the date stock reward of the post-merger and acquisition is negative correlation As to the effects of post-merger and acquisition companies’ long-term performance in risk aspect the risk of stock market is positive significance but the whole risk is negative significance In business synergy there is a decline in the post-merger and acquisition However compare to other companies in the same industry there is no significance showing the post-merger and acquisition companies inferior to the others The degree of earnings management of the pre-merger and acquisition companies and the post-merger and acquisition performance is negative significance The relationship between the degree of earnings management of the pre-merger and acquisition companies and the post-merger and acquisition stock reward is negative significance Nevertheless the relationship to the post-two or three -year merger and acquisition is no significance and it reveals that earnings management has effects on stock price in first year Moreover the post-merger and acquisition stock reward has no relationship with the pre-merger and acquisition earnings managemen