本研究欲探討公司是否能藉由併購進而產生出綜效,針對台灣及韓國公開發行公司 的國內併購交易做實證研究。學術上新古典經濟學之併購理論多認為 Q 比率高的公司 併購 Q 比率低的公司,市場投資人會認為其創造較高的價值,也就是俗稱之綜效。但也 有部分研究認為,低 Q 比率的主併公司併購高 Q 比率的目標公司,提高主併公司的長 期成長性、管理手法或是減少日後的競爭威脅。本研究使用 Bradley, Desai and Kim (1988) 提出之合併股價累積異常報酬計算綜效,以避免傳統僅考慮主併公司的偏誤。過去學界 多以市值帳面比(M/B ratio)做為前述 Q 比率之代理變數,本研究藉由 Rhodes-Kropf, Robinson and Viswanathan (2005)評價模型,排除 M/B ratio 定價錯誤之部分,推導出與公 司基本面緊密相關之 V/B ratio 改做為 Q 比率之代理變數,發現可提高公開發行公司併 購交易行為之解釋力。在台灣樣本,V/B ratio 較低的主併公司併購 V/B ratio 較高的目標 公司可以創造較高的併購綜效;韓國樣本則為 V/B ratio 較高的主併公司併購 V/B ratio 較低的目標公司可以創造較高的併購綜效。本研究亦同時考量目標公司相對主併公司市 值規模大小如何影響綜效,結果發現台灣樣本目標公司相對主併公司市值規模大小增加, 合併公司累積異常報酬增加;韓國市場投資人則偏好目標公司佔合併公司規模 6%至 27%的併購案。本研究歸結兩國國內併購案結果不盡相同,主係因韓國則是以製造業為 主,而台灣併購案以高科技業居多。本研究深入檢視台灣高科技業併購案,發現結果大 致相同,且較台灣全部樣本更為顯著,故認為除了傳統的 Q 理論以外,主併公司可以透 過併購創新技術取得成長機會,增加宣告報酬,並且使合併後公司價值上升。;I focus on synergies driven by difference in Q ratio and relative sizes among acquirer and target firm in a merge and acquisition case. Neoclassical theory indicates a high-Q acquirer with a low-Q target can can reallocate the target’s asset to increase announcement return, operating performance and creates value for combined firm; while a low-Q acquirer can benefit from a high-Q target by maintaining long-term growth opportunities, improving management skills, or eliminating potential threats. I follow Bradley, Desai and Kim (1988) to measure the synergies by computing combined cumulative abnormal return. I use the decomposition introduce by Rhodes-Kropf, Robinson and Viswanathan (2005) to eliminate the mispricing in M/B ratio, and use V/B ratio for a better Q proxy. I find investors preferred low V/B ratio acquirer and high V/B ratio target for M&A cases in Taiwan; but high V/B ratio acquirer and low V/B ratio target for cases in South Korea. As for relative size (RS) among the acquirer and target, I find larger RS yields higher combined CAR in Taiwan M&A deals, while target accounts for 6% to 27% combined firm can generate the most value in South Korea M&A deals. Moreover, I find high-tech deals driven the empirical results in Taiwan, and that explain how a low-Q acquirer can benefit from a high-Q target by acquiring growth opportunities and creates value for combined firm.