本研究將我國獨立專家可能發揮之功能分為能夠認證交易係公平且無弊端之「消極認證功能」及能積極預測綜效並為市場排除不具綜效交易之「積極認證功能」，並藉由分析代理成本與獨立專家選擇之關聯性，以及獨立專家自我選擇與併購後綜效之關聯性，實證探討我國獨立專家制度之運作概況及其功能。 研究結果發現，衡量代理成本之公司及交易特性變數中，負債比率較高、外部大股東持股比率較低、機構投資人持股比率較低、併購溢價較高、主併與被併公司相對規模較接近時，公司聘僱高聲譽獨立專家的可能性較高，支持我國獨立專家可能具有降低代理成本之消極認證功能之論點。積極認證功能方面，本研究發現，以併購金額市佔率衡量獨立專家聲譽時，高聲譽獨立專家簽發評價報告之併購案，併購後市場佔有率成長幅度較高，支持我國獨立專家可能具有積極認證功能之論點，但僅限於市場綜效部分。 / This study tests whether the negative certification function and positive certification function are important service performed by independent experts in the M&A transaction. It conducts an empirical investigation of the choice of independent experts and the synergy in the M&A transaction. The result demonstrates that when the debt ratio is high, the percentage of stock owned by institutional owners and external shareholders is low, the premium is high, and the size of acquirer and target is similar, acquirer tends to hire a more prestigious independent expert. It confirms that the negative certification function exists. In addition, we find that when the reputation (measured by market share) of independent experts is high, the market synergy in the M&A may be higher than others. It is because of that the independent experts tend to protect their reputation by choosing their clients rigorously. Therefore, the positive certification function is also confirmed.

本研究以2002年至2012年台灣主併公司為上市公司的併購案件為樣本，探討合理性意見書評價內容和主併公司短期股價影響及併購後綜效之關聯性。研究結果發現，於意見書揭露日時，若獨立專家評估價格高於雙方約定交易價格愈多時，即評價溢酬愈大，或是評價報告由高聲譽獨立專家所出具，主併公司會有正向的累積異常報酬率；且在此情況下，主併公司併購後綜效亦會愈大。故本研究認為，合理性意見書中的評價資訊，於揭露時具有訊號發射效果，可以幫助外部股東及投資人判斷交易是否對其有利，降低內外資訊不對稱，同時亦具有認證併購後公司會產生合併綜效之功能。因此，併購時獨立專家所出具之合理性意見書確實具有資訊意涵。 / This study analyses the relation between target firm valuations disclosed in the fairness opinions and acquiring firm performances by using the samples of Taiwanese listed company in M&A transaction between 2002 and 2012. We find that the stock price reactions to the public disclosure of fairness opinions are positively related to the difference between target firms valuations contained in the fairness opinion and the merger offer price and the reputation of independent experts. Under these conditions, the synergy in the M&A may be higher than others. Therefore, we suggest that the information contained in the fairness opinions can not only reduce information asymmetry between management and stockholders, but also certify that the M&A transaction will produce synergy. We conclude that fairness opinion does contain useful information to market participants.