本篇論文分成兩部分的實證，第一部分為「券商的利益衝突」；第二部分為「券商在報紙公開推薦但實際上所買賣的個股是否有顯著異常報酬」。 　　第一部分為檢視券商在民國九十一年至九十三年六月底於工商時報及財訊快報每週固定推薦之個股，券商在消息公佈前後期間是否有產生利益衝突的行為。吾人所建構的利益衝突指標分別以買賣次數、買賣金額及買賣股數來衡量。實證結果發現，券商不論是在消息公佈前後一週或公佈前後兩週其利益衝突的行為皆不明顯，簡言之，券商不論在買賣次數、買賣金額或買賣股數上皆無明顯的利益衝突行為。 　　第二部分則是根據第一部分券商於民國九十三年一月至六月底於報章雜誌上公開推薦並實際上有買賣的股票，檢視這些股票是否在消息公佈後產生正的異常報酬。實證結果發現，在股票公開推薦日之前，券商根據公開推薦之個股實際上有進行買賣的股票，其股票報酬率的績效呈現高於市場投資組合績效之趨勢，亦即股價對該推薦事件發生之前已有反應；在公開推薦日之後，CARt一路呈現下降走勢，若投資人在事件日（股票公開推薦日）才得知被公開推薦之股票消息時，因股價已調整完畢，投資人將無法由此項公開消息獲得超額報酬，亦即在消息日發佈後股票公開推薦資訊對股票報酬率並無產生顯著反應。 而有關台灣股票市場「半強式效率市場」的檢定，實證結果發現，股票公開推薦並未對股價造成一致性且持續的影響，投資人無法從券商股票公開推薦中獲得超額報酬，就以上兩點而言，台灣股票市場具有「半強式效率市場」之特徵。

本研究旨在以投資大眾的角度出發，研究正、負面企業社會責任事件宣告如何影響投資者的投資決策，進而影響股價產生異常報酬。實證結果發現，正面企業社會責任事件宣告將產生顯著為正的股價異常報酬；負面企業社會責任事件宣告則將產生顯著為負的股價異常報酬。另外，本研究針對負面企業社會責任事件所產生的累積異常報酬建立了複迴歸模型，探討企業規模、企業所屬產業及負面企業社會責任事件宣告之消息種類與該累積異常報酬是否存有關聯性，實證結果發現，大型企業、宣告之消息種類屬於資訊公告問題者，與該累積異常報酬呈現顯著負相關；企業屬於高汙染產業者與該累積異常報酬呈現顯著正相關。本研究除了瞭解企業社會責任資訊如何影響投資者的投資決策外，更希望能提供企業經營者作為經營策略之參考。 / Abstract The purpose of this study is to investigate the market reaction of positive and negative CSR announcements. The empirical results show that there is a significant positive (negative) relationship between positive (negative) CSR announcements and abnormal stock returns. Furthermore, this study establish a regression, trying to find whether company size, business industry, type of negative CSR announcements will have a relationship with negative CSR announcement’s abnormal returns. The author of this research hopes that the findings in this study can not only understand how CSR announcements effect the investors but also help managers develop a CSR strategy.

本研究主要介紹「結合決定的事後評估」(ex-post evaluations of merger decisions)中常用的「事件研究法」，篩選出國內重要之水平結合案件，以事件研究法(event study)針對結合參與事業與其水平競爭事業進行完整的事後評估，並將估計結果以市場力量假說(market power hypothesis)、效率假說(efficiency hypothesis)及其他經濟理論加以解釋。 研究結果發現，結合參與事業與其競爭水平事業在結合事件期間之累積異常股價變化與效率假說的預測部分一致，拒絕了市場力量假說，效率假說指出水平結合案會使參與事業之股價上升，因結合案會導致規模經濟或協同效應，提高企業之生產效率，降低成本進而增加利潤，但對其水平競爭事業的股價影響並不確定，取決於協同效應 (synergy) 與資訊紕漏效應 (information revelation)作用之大小，而研究結果也發現競爭法主管機關之結合決定並未完全被市場所預期。 本研究結果也指出，參與結合的主併公司其累積異常報酬率之正負值與被併的目標公司營運情形息息相關，若目標公司長年虧損，會使市場不看好此結合案，導致主併企業之累積異常報酬為負值；若結合參與事業生產之商品為同質性（本研究為不鏽鋼平板），可能會影響雙方之生產力下降，使結合參與企業利潤下跌進而影響股價下滑，表示市場不看好此結合案。

以往研究政治景氣循環之文獻，焦點集中在經濟表現、股市漲跌和執政黨連任之關係。但是，由於選舉結果也會直接影響到一個國家的股市後勢，因此政治選舉事件的結果對市場參與者尤其重要。本研究以不確定資訊、過度反應及追漲殺跌理論，為實證發展的架構，實證研究各國股市行為對於正事件或是負事件的選舉結果如何影響股市的後勢表現。 本文以10個國家的政治選舉事件，實證正、負事件的選舉結果對股市後勢的影響，並檢視重大選舉事件對股價變化究竟符合不確定資訊、過度反應及追漲殺跌理論何種理論。研究方法為事件研究法，並同時考慮以OLS與GARCH的模型來配適分析。 實證結果發現不論以OLS或是GARCH的模型來配適分析，在建立預期報酬率模型上或有些許的差異，但最後皆能得到一致之結論。本文結論如下: 1.支持不確定資訊理論者，無。 2.支持過度反應理論者，計有台灣、法國、英國、新加坡。 3.支持追漲殺跌理論者，計有泰國。 4.皆不支持上述三種理論者，計有加拿大、西班牙、紐西蘭、德國、澳洲。

本研究探討台灣50指數成分股變動造成的異常報酬與超額交易量現象，提供投資人作為選股參考，由於台灣50指數編製依據為總市值，僅使用公開資訊，可以用來檢驗效率市場假說。不同於過去研究的貢獻，本文考慮金融資產報酬的波動群聚現象及模型係數的不穩定性，分別使用卡爾曼濾嘴法及GARCH(1,1) 模型修正，以期獲得較穩健的實證結果。本研究結果發現，新增股及剔除股在宣告日的下一個交易日及生效日的前一個交易日有顯著異常報酬；新增股的累積異常報酬可持續大約兩個工作星期，且新增股有持續的超額交易量情形；而剔除股僅在生效日及生效日的前一個交易日有超額交易量。上述實證結果顯示投資人可利用此公開資訊，獲得異常報酬，不支持效率市場假說。 / We study the price and volume effects following the Taiwan 50 Index revisions. Since the decision to include (exclude) a stock in (from) the index is based merely on market capitalization, it provides a unique opportunity to test the efficient market hypothesis. Our contribution to the existing literature lies in the fact that we employ the Kalman filter approach and the GARCH(1,1) model to allow the parameters instability and time-varying residual variance, and hence to produce more robust empirical results. The results suggest that the newly added stocks and the currently dropped stocks experience significant price changes right after the announcement day and right before the change day; the abnormal returns of the newly added stocks last about two weeks, these stocks also exhibit persistently excessive trading volume while the currently dropped stocks only have excessive trading volume on and right before the change day. These results indicate that investors can earn abnormal returns through public information, and invalidate the efficient market hypothesis.

在競爭激烈的產業環境中，企業必須具有產品價值的創造能力，才能開發新產品以滿足顧客的需求。故本研究欲探討當企業宣告取得專利權、專利授權與代理權促使競爭優勢提升之資訊內涵。本研究以民國94年及95年宣告取得專利權、專利授權與代理權之公司，及依同產業及相似公司規模配對之公司組成研究樣本。首先以事件研究法探討宣告樣本是否能獲得正向報酬，並將樣本分為專利權、專利授權與代理權三組子樣本以觀察不同競爭優勢對報酬影響之程度是否有差異，最後再將專利權樣本分為發明專利與新型式專利兩組子樣本以瞭解不同種類專利權對報酬影響之程度是否有差異。實證結果如下：一、當企業宣告取得專利相關競爭優勢時，有正向報酬產生。但惟有當企業宣告取得專利授權與代理權時才能獲得顯著正報酬；二、企業宣告取得不同競爭優勢對報酬影響之程度有差異，企業宣告自行研發專利與取得專利授權所能獲得的報酬有顯著差異，宣告自行研發專利與取得代理權在事件宣告後的報酬有顯著差異，而宣告取得專利授權與代理權所能獲得的報酬則無論短期或長期皆無顯著差異；三、企業宣告取得發明專利或新型式專利，兩者所能獲得的報酬並無差異。 / In the keenly competitive environment、enterprises must have the abilities of product value creation to develop new products and to satisfy customers』 demand. So this essay want to discuss the information content that enterprises announced that they acquired patent、patent licensing、and authority of agency to enhance competitive advantage. Based on the use of a control sample design and the firms selected have announced acquiring patent、patent licensing、and authority of agency in 2005 or 2006、and are listed on the Taiwan Security Exchange or the OTC. At first、this research employs event study to discuss whether sample of announcement could acquire positive abnormal returns. And then、in order to compare the degree of returns affected by different competitive advantage、this research divided the whole sample into three subsamples including patent、patent licensing and authority of agency. Finally、it also divided patent sample into two subsamples including invention and non-invention in order to compare the degree of returns affected by different types of patent. The empirical finding indicates that (1) when enterprises announced that they acquired competitive advantage、they will have positive abnormal returns significantly. However、only enterprises announcing that they acquired patent licensing and authority of agency could have positive abnormal returns significantly. (2) The degree of returns affected by information is different from different kinds competitive advantage、especially between patent and patent licensing、and between patent and authority of agency. (3) When enterprises announced to acquire different types of patent、they will have insignificant variance of abnormal returns.

本文研究自1997年至2007年，dotcom公司更名之長期與短期宣告效應，樣本包括名稱增加dotcom或剔除dotcom的兩類公司。過去文獻指出dotcom公司更名在-30天到+30天期具有顯著為正的累積超額報酬。與以往文獻不同，我們關心dotcom公司更名帶來的正報酬是否能持續，抑或宣告後的效果終將轉為負報酬，減損股東財富。實證結果顯示，雖然在事件日出現顯著3.14%的正累積超額報酬，但120天與360天事件窗口累積超額報酬均為顯著負值，分別為-55.52%與 -156.09%，所以dotcom公司更名的妝飾效果(cosmetic effect)為暫時的現象。故在長期，投資人若在網路熱潮時期買進新增dotcom於其名稱的公司的股票，損失很可能會隨著時間而擴大。此外，我們也發現更名公司的基本價值(fundamental values)在更名的前後兩年並無顯著差異，因此投資人對於股價的反應僅基於情緒(sentiment)，而非出於他們對基本價值的觀察。另一方面，研究樣本公司在 I/B/E/S資料庫中的一致性分析師盈餘預測，發現分析師對此類更名公司的下一季盈餘預測往下修正，但此下修應屬系統性現象。在預測誤差方面，分別探討網路熱潮期與冷卻期的預測誤差後，發現後者為-$0.2650，具有10%顯著水準。故可推論此時期分析師所掌握的資訊較為不足，或是來自世界各地的分析師意見不一致。此外，由於分析師盈餘預測可代表投資人對市場的預期，故在網路冷卻期，投資人對更名公司股價的反應是不理性的。 / This paper investigates long-term versus short-term effects of dotcom corporate name changes from 1997 to 2007. The sample contains a combination of name change events on which firms add dotcom to, or remove dotcom from their names. We attempt to examine whether announcement effects of dotcom name changes last long, or are prevailed by post-announcement negative drift eventually. On the announcement date, we find firms earn significant abnormal returns on the order of 3.14%. However, firms yield negative CARs over the 120- and 360- day window, which are -55.52% and -156.09%, respectively. These results suggest that firms can create shareholder’s wealth by dotcom name changes, but cosmetic effects of their name changes are simply transitory. Due to this finding, we suggest investors who experienced loss on stocks of dotcom addition firms should aware that their loss continues growing as time goes by. Next, the fact that fundamental value of our sample firms does not change significantly indicates that investors are affected by market sentiment, rather than driven by changes of fundamental value. Furthermore, we examine consensus analysts’ EPS forecasts from I/B/E/S database. EPS forecasts are used as proxies of investors’ expectations. We find analysts revise downwards in EPS forecast changes of name change firms. However, there is no significant difference between the sample and the benchmark group, in terms of forecast changes. Accordingly, we conclude that analysts systematically revise their estimates downward. Moreover, forecast errors in the Internet-cold period is $-0.2650 and significant at 10 percent level. We infer that analysts do have sufficient information or consensus. Thus, investors are irrational in response to dotcom name change announcements in the Internet-cold period.

本研究首先採事件研究法探討第34號公報第二次修訂公報發布時，市場反應與是否具備資訊內涵。其次針對公司之季報發布日公司所揭露之損益影響數，研究市場對於公報第二次修訂後第一個盈餘公布時點之反應，再以Ohlson 評價模式，來驗證所揭露之損益影響數是否具價值攸關，投資人對此事件反應為何。採用logit及一般迴歸，分別探討影響公司重分類動機的因素及影響公司重分類金額多寡之因素加以實證分析。 實證結果顯示在公報修訂發布日及季報發布日具資訊內涵及價值攸關 ，投資人並有功能性固著現象產生。就重分類動機而言，當公司董監質押比率越高、TCRI信用評等等級越高、非四大會計師事務所核閱之客戶、淨值報酬率越低越傾向重分類金融資產。而就重分類金額多寡而言，董監事質押比越高、TCRI信用評等等級越高、非四大會計師事務所核閱、股利配發率越高、淨值報酬率越低，重分類之損益影響數金額越大。 / This research mainly focuses on the market responses and its information content against the second amendment re-classification of SFAS NO.34 of financial assets using event study methodology. Market responses is examined with the amount disclosed at the first announcement of quarterly report. Then Ohlson model is applied to verify whether the disclosed amount has value relevance and how investors react to the announcement. The logit and OLS regression is utilized to examine the rationale behind reclassification and what affects the amount of reclassification. The empirical result shows that the announcement date of second amendment and announcement date of quarterly report do retain information content and value relevance. The investors have shown significant functional fixation. Higher pledged share ratio of directors and supervisors, lower ROE and higher TCRI rating, and is not reviewed by big four audit firms, is positively related to reclassification of financial assets. The amount of reclassification is positively related to higher pledged share ratio of directors and supervisors, higher TCRI rating, higher dividend payout ratio, is not reviewed by big four audit firms and lower ROE.

隨著經濟走向自由化、國際化，且台灣亦公布企業購併法後，合併及收購等外部成長模式逐漸受到重視，而台灣證券交易市場目前資本來源比重也與過去以散戶為大宗的情況有別，近年來機構投資人交易扮演重要的角色，故本論文希冀探討機構投資人交易與台灣上市主併公司購併宣告效果的關聯。 本論文以台灣購併案件為探討對象，排除金融業相關案件，取樣自2003年至2012年間宣布購併的交易案件，以三大法人（外資法人、投信公司、證券自營商）為機構投資人代表，並且採用其每日買（賣）超股數占總流通股數比例做為交易指標，分別以市場模型及市場指數調整模型計算累積異常報酬率，探討機構投資人交易是否隱含對投資標的經營團隊品質的認證價值，進而反應在主併公司在（-1,+1）、（-2,+2）、（-3,+3）事件窗口下之購併宣告效果。 實證結果主要有以下幾點發現：首先，本研究發現三大法人累積淨買（賣）超與主併公司購併宣告累積異常報酬率在即期事件窗口（-1,+1）及（-2,+2）下均呈現顯著正向關係；第二，獲得三大法人累積淨買超之主併公司之購併宣告累積異常報酬率在（-1,+1）期間顯著高於三大法人累積淨賣超之主併公司，顯示機構投資人交易對主併公司經營團隊有品質認證價值；第三，三大法人中外資法人累積淨買（賣）超與主併公司購併宣告效果有顯著正向影響，而投信公司、證券自營商則與主併公司購併宣告後累積異常報酬率無顯著關係。 / This study investigates the relationship between institutional trading and the announcement effect of merger and acquisition. The research is based on acquiring firms listed in Taiwan which announced merger and acquisition between 2003 and 2012. We use cumulative net buying of three representative institutional investors including foreign institutions, mutual funds, and brokers to examine acquirer’s short-run stock performance around the announcement of merger and acquisition. First, the results indicate that cumulative net buying of total institutional investors is positively related to the short-run stock performance of acquirers. Second, acquirers with increase in institutional holdings prior to the merger and acquisition have better short-run stock performance than acquirers with decrease in institutional holdings. Third, the relationship between cumulative net buying of foreign institutions and the announcement effect of acquirers is significantly positive while cumulative net buying of mutual funds or brokers has no significant relationship with the short-run stock performance of acquirers.

本文沿襲事件研究法的精神，首次將有無資訊的分類帶入漲跌幅限制的實證研究中。過去的文獻對於漲跌幅限制的效果，一直無法在理論或者實證上得到一致的結論，綜觀正反論辯，投資人對於資訊能否理性反應到股價上，是雙方交鋒的重點，因此假若能將造成漲跌幅事件背後的資訊本質釐清，將有助於吾人了解漲跌幅限制真正的影響。 本文利用個股的公開消息定義漲跌停事件的資訊本質，觀察漲跌停事件前後二十四小時股價、波動性與週轉率的變化，結果比較支持漲跌幅限制可以抑制過度反應的說法，不過漲跌幅限制卻在漲跌停板的前後，均造成較大的波動性與週轉率。此外，有資訊的漲跌停事件與沒有資訊的漲跌停事件，兩者的差異不如推論明顯，可能原因是存在本文無法捕捉的私有資訊。