指導教授：盧信銘臺灣大學：資訊管理學研究所孫久悌Sun, Caroline JouteeCaroline JouteeSun2014-11-292018-06-292014-11-292018-06-292013http://ntur.lib.ntu.edu.tw//handle/246246/263485　　併購是會對收購方公司造成異常報酬的事件。本研究探討新聞報導對併購事件的影響，以及其可能對併購宣告前在收購方公司新聞中共同出現（co-occurrence）的其他公司所造成的外溢效果。我們使用1990年至2008年華爾街日報的新聞資料，並以事件研究法來探討新聞報導對併購事件的影響。若以「第0天」代表併購宣告日，並觀察[-20,-3]期間的新聞報導，研究結果發現在[-1,+1]期間，無新聞報導的收購方公司比有新聞報導的收購方公司的異常報酬高了1.130%。若觀察宣告日前後較長的期間，我們也發現無媒體報導溢價（no-media premium）。在使用公司特性為收購方公司分組後，我們進一步看到無媒體報導溢價在各個分組中有不同的表現。此外，新聞報導的時間點也會對於併購事件的報酬造成影響。然而，我們並未發現共同出現公司有異常報酬。Mergers and acquisitions are events that may cause abnormal returns to the acquirers. In this study, we study the impact of news coverage on the M&A events and the potential spillover effect of co-occurring firms in news before event announcement. Based on the news coverage computed from the Wall Street Journal from 1990 to 2008, we studied the effect of news coverage on M&As using the event study methodology. Our study finds 1.130% of no-media premiums in the [-1, +1] period using news coverage of the [-20, -3] period. (“Day 0” denotes the announcement date.) There are also no-media premiums in longer periods before and after the announcement. The no-media premiums differ in the groups of firms of different characteristics. The release time of news also affects the returns of M&As. However, we do not find abnormal returns of the co-occurring firms.Table of Contents……………………………………………………………………………………………………………i List of Tables………………………………………………………………………………………………………………iii List of Figures………………………………………………………………………………………………………………iv Chapter 1 Introduction………………………………………………………………………………………………1 Chapter 2 Literature Review…………………………………………………………………………………5 2.1 The Media and the Stock Market……………………………………………………5 2.2 Market Reactions of M&A Events……………………………………………………8 Chapter 3 Data and Empirical Model……………………………………………………………11 3.1 Data and Descriptive Statistics…………………………11 3.2 Empirical Model…………………………………………………………………………………………17 3.2.1 CAPM and Fama-French Three-Factor Model……18 3.2.2 Method for Calculating the Cumulative Abnormal Returns of M&As………………………………………………………………………………………………………………18 3.2.3 Method for Calculating the Cumulative Abnormal Returns of Co-occurring Firms…………………………………………………………………………20 3.2.4 T-test for the Differences in Mean Between the Groups………………………………………………………………………………………………………………………………………21 Chapter 4 Results…………………………………………………………………………………………………………22 4.1 Abnormal Returns around Announcement Date: Short Window………………………………………………………………………………………………………………………………………22 4.2 Pre-Announcement and Post-Announcement Returns: Long Window………………………………………………………………………………………………………………………………………25 4.3 Returns with Different Degrees of News Coverage……28 4.4 Returns Sorted by Firm Characteristics……………………………30 Chapter 5 Conclusion…………………………………………………………………………………………………32 Appendix…………………………………………………………………………………………………………………………………34 References……………………………………………………………………………………………………………………………36523158 bytesapplication/pdf論文公開時間：2019/01/27論文使用權限：同意有償授權(權利金給回饋學校)併購新聞報導共同出現事件研究法異常報酬thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/263485/1/ntu-102-R00725030-1.pdf