本研究透過各公司之自然人、創投、法人和國發基金董監事與經營團隊變動，探討四者之董監事與經營團隊在IPO之後是否因為內部資訊掌握差異，所造成的經營團隊結構改變。實證結果發現在IPO之後四者都有明顯的變動，故推斷依照基本特性推斷以下四個結果：(1)內部自然人的確有利用內部資訊進行IPO後拋開經營權之嫌；(2) 創投因為其本身就為獲利導向，故其是否利用內部資訊退場無法下定論，但可知道創投確實在IPO之後會在短時間內退場；(3) 企業法人因其介入目的大多為策略導向，故其雖亦會利用內部資訊，但並非以賺取不公平獲利為導向；(4) 國發基金身帶政策性目的和進出有其目標設定，故內部資訊之應用並非重點。還有，內部人之關係連結確實會增強內部資訊之流動。

在公司績效的決定因素的研究中，本研究採用Marginal q作為衡量企業投資效率的指標，發現內部人持股比例與公司經營績效間之關係綜合「利益收斂說」以及「掠奪性假說」兩種效果，隨內部人持股比例呈倒U字形先增後減的非線性關係。其他控制變數方面：機構投資人能擔任監督管理者的角色、有效降低代理成本增進公司價值；規模對公司績效大致呈正面影響，惟效果並不顯著；在Tobin's q模型，研發活動支出比例對公司績效有正面的影響；在Marginal q模型，研究發展支出比例對公司績效影響不顯著。本研究亦考量董監質押比例的影響，結果顯示，公司績效僅與董監質押行為負相關與質押比例則無顯著關係。本研究亦採用一個新的衡量內部人持股變數—平均每位董事/監察人持股，該變數亦能精確衡量內部人持股。考量模型內生性的問題後，內部人持股比例與公司績效之關係，並未因此改變。 / We investigate the determinants of the performance of the firm measured by Tobin's q and Marginal q in our study, and find a curvilinear relation between firm value and insider ownership. The traditional measure, Tobin's q, suffers from several drawbacks. Among which the endogeneity is the most serious one which may cause the relationship spurious. As for other controlling variables, we found that institutional investors are able to supervise the management effectively, which implies lower agency cost. The size of the firm is contributive to the value of the firm; however, the influence is not significant. R&D has positive and significant impacts on Tobin's q as we expect. There is less reason to expect a positive relationship between R&D and Marginal q. Indeed, we didn’t find any significant relation in our regression result. We also include the mortgage ratio of the insiders in our study. We conclude that performance is related to whether the insiders mortgage or not. The extent of mortgage doesn’t matter. We construct a new variable –average insider ownership– which could also measure the extent of insider holding well. Considering the possibility of endogeneity, the relation between insider ownership and performance of the firm is still consistent with the result of our study.

以往有許多研究從內部人學經歷、性別、平均任期等外生變數去探討內部人與公司租稅規避之關聯性，甚少去藉由內生變數的面向去探討內部人與租稅規避之關聯性。因為個人的納稅資料難以取得，本研究藉由分析財政部訴願決定書的內容去衡量內部人個人是否具備租稅規避的傾向，而其中個人是否具租稅規避傾向的判斷標準是根據所得稅法第66條之8的規定。本研究的實證結果顯示，當內部人個人具租稅規避傾向時，其管理之公司租稅規避程度較高，可以推論其在管理公司時會採行較多租稅規避的政策。 / Many prior studies uses exogenous variables such as insiders’ educational background, gender and average serving year, to discuss the relation between insiders and tax avoidance. It is difficult to attain personal tax information, so this research analyze the administrative appeal decision from Ministry of Finance to measure whether insiders have the characteristic in avoiding tax. This research assume insiders have tax avoiding characteristic if insiders violate income tax law 66-8. The empirical result of this research shows that when insiders incline to avoid personal income tax, the company insiders serve avoid more tax. This research thereby infer insiders with tax avoiding characteristic adopt more tax avoiding policy when managing company.

本篇論文探討在台灣獨有的先申報後轉讓的內部人交易制度下，到底內部人申報轉讓後之執行率公布對一般大眾的影響為何呢？內部人申報轉讓後，有可能實際轉讓，也可能不轉讓或不足額轉讓，端視內部人的策略。我們把焦點放在內部人申報轉讓持股後，當市場公布執行結果後，個股交易量的表現為何。結果發現異常交易量因執行率公布後獲知內部人之淨買淨賣行為而有所增加；但內部人無淨買賣時,交易量無明顯異常。

本研究結合Easterbrook (1984) 與John & Williams (1985)之理論基礎，探討在資訊不對稱且股權高度集中的台灣市場，是否現金股利之發放，其內含資訊對外部股東是一個利多消息外；對內部股東而言，發放現金股利除了受益自身，還可以提升現金增資期間之公司股價，使公司有能力與承銷商議定較高的承銷價，減少新發行之股數來避免股權稀釋，以維持原股東之控制權。本研究針對民國84年到民國92年間現金增資的公司，依照現增前有無發放現金股利為基準，將樣本區分為二，檢定現金股利是否對增資期間的股價與增資後內部人股權稀釋程度有顯著影響。 有關實證結果說明如下： 一、增資前有發放現金股利之公司，其股價表現的確優於未發放現金股利者，不論長短期股價表現，皆達統計上之顯著水準，證實現金股利的確具有資訊內涵。 二、承銷價定價參考期間中，現增前有發放現金股利的公司，其於證管會核准日前一到兩個月之股價異常報酬(AR)與累積異常報酬(CAR)，顯著優於未發放現金股利的公司。故發放現金股利的確有助於現金增資承銷價之提升。 三、有發放現金股利的公司，其內部人或是董監事之持股稀釋程度明顯小於未發放者。驗證了John & Williams (1985) 提出股利可減輕增資後原股東股權稀釋之問題的論點。 四、迴歸模型中，現金股利之發放的確能減輕內部人股權稀釋幅度，兩者呈現極顯著的負向關係；現金增資規模對稀釋幅度之影響不顯著；而內部人於現增前之持股率則和稀釋幅度呈顯著正相關；Market to Book Ratio (MB)對股權稀釋幅度無顯著影響。

We investigate the trading strategy of the insider and propose two models to describe the insider’s behavior. Comparing with previous studies, we add insider stockholdings as a variable to the extension of information asymmetry. In our setting with information asymmetry between outside investors and the insiders, the insiders could obtain more inside information via increasing their stockholdings. When the insider with large stockholdings purchases more shares, outside investors would take this as a positive signal that the insiders regard the performance of the company in the future as optimistic. On the other hand, when the insider stockholdings is large, outsiders would worry that inside trading may become more. The insider would deliberate upon the quantities traded at period one and two, which have different impact in stock price. If the insider buys more stocks at period one, he could improve his information precision. However, if the insider buys large stocks, the market makers would take into account the insider’s function of information precision and thus the insider may impact on the stock price. Therefore the insider would evaluate market makers’ pricing rule. Since increasing stockholdings enhances precision information, intuitively, earlier stage the insider submits a large order. Nonetheless, our study shows that when the insider stockholding is extremely large, then the increasing of information precision is limited because the information precision is increasing with insider stockholding at a decreasing rate. Besides, when the insider stockholdings is large enough at period one, he would place a small order at period two.

台灣上市公司為了轉型、多角化及提升競爭力等需求，經常轉投資於其他事業體，不同於其他歐美國家，台灣母公司通常未持有轉投資公司全數股權，而且經常有一部份股權是由母公司董監事、高階經理人及大股東等內部人所持有，此即本論文研究主題—內部人參與投資母公司轉投資事業。由於資訊不對稱下存在的代理問題，內部的參與投資母公司轉投資事業又改變了內部人報酬來源之結構，內部人動機及行為可能因而改變，進而影響轉投資績效及母公司價值。內部人參與投資母公司轉投資事業理論上有其重要性，但目前文獻尚未對此一現象之成因及影響進行探討，因此本論文針對內部人參與投資課題進行研究。 本論文取樣自台灣證券交易所在2001年底以前上市的74家各產業大型公司，藉由假說建構及變數的設計，以內部人參與投資為中心，本論文包含了三個研究課題，第一個課題關於轉投資事業間內部人參與投資差異性之成因；第二個課題是關於不同公司間內部人參與投資程度差異性之成因；第三個課題是檢視內部人參與投資對公司價值的影響。 在第一個課題轉投資業間內部人參與投資差異性成因方面，實證結果發現：母公司對轉投資事業持股比例愈高，參與投資比例愈低，支持「股權結構替代性假說」。對多數樣本而言，內部人對於有兼職的轉投資事業有較高的參與投資程度，支持「激勵機制假說」。內部人較傾向於參與投資與母公司經營無關行業的轉投資事業，支持「內部人投資多角化假說」。而「利益輸送因應假說」、「擇優投資假說」以及「內部人財務限制假説」並未受實證結果支持，可能代表對利益輸送效果之因應、追求具良好報酬特質的投資標的以及對自身財務限制之考量，並非內部人參與投資決策時的主要考量因素。 在第二個課題公司間內部人參與投資差異性之成因方面，實證結果發現，內部人參與投資會隨負債比例及轉投資組合比例而增加，表示內部人參與投資可能是為了解決母公司轉投資時資金來源的問題，支持「解決母公司財務限制假說」。而參與投資也會隨內部人兼職轉投資組合程度而增加，符合「激勵機制假說」之預期。內部人會因轉投資組合與母公司之間的契約交易關係密切，而增加其相對參與投資比例，符合「利益輸出因應假說」之預期。內部人參與投資比例平均值與母公司對轉投資事業持股比例平均值，呈顯著負向關係，支持「股權結構替代性假說」。而不論是轉投資組合規模、母公司規模或是局部轉投資組合相對規模，都對參與投資程度有顯著正向影響。未能受到本部份實證支持的假說包括「擇優投資假說」、「內部人投資多角化假說」、「直間接投資替代性假說」、以及「控制權補強假說」。 在第三個課題參與投資對公司價值的影響方面，實證結果發現參與投資比例中位數對轉投資組合報酬率有正向影響，支持「激勵誘因假說」，可以推論參與投資的激勵誘因效果，主要是來自於投資對象較為普遍，而不集中於少數轉投資事業的參與投資型態。除了少數分類樣本外，並未發現支持「內部人自利選擇假說」的直接證據。 在內部人控制權力集中以及家族控制公司，參與投資對公司價值的影響不論正負，都更為顯著；這可能是因為內部人參與投資最主要是透過影響內部人動機而影響母公司價值，由於這類公司的內部人比較能主導公司決策及營運，故內部人動機改變造成的效果會愈為顯著，造成了內部人參與投資對母公司價值有較為顯著的關聯性。而市場對於電子業內部人的參與投資評價似乎特別正向，可能是因為市場將內部人參與投資解讀為其對公司轉投資事業的認同。 / The large corporations in Taiwan often invest in other firms, namely the parent corporations own equity stakes of their subsidiaries. Interestingly, the insiders of parent corporations (including the directors, supervisors, senior managers and large shareholders of parent corporations) also frequently invest in these subsidiaries at the same time. I name this phenomenon co-investment. With the sample of 74 largest TSE-listed corporations of 17 industries, this empirical paper tries to investigate the causes and impacts of co-investment. The empirical results show that the degree of co-investment is negatively related to the equity stake hold by the parent corporations. The co-investment seems be used as an incentive mechanism, which can encourage insiders to improve the performance of subsidiaries. Insiders co-invest in those business-unrelated subsidiaries more likely, which is consistent with the “diversification hypothesis”. Those parent corporations with more transaction-related subsidiaries (TRS) have higher degree of co-investment, which implies that insiders may take the benefits of tunneling by increase their equity stakes of TRS. There are also some empirical results support that insiders co-invest in subsidiaries to finance the investment need of parents corporations. Although co-investment may reform the return source of insiders and theoretically deteriorate the incentives of insiders, however, this paper finds no strong evidence that co-investment would do harm to the value of parents corporations. One special type of co-investment may increase the performance of subsidiary portfolio and the value of parent corporations.

本研究旨在探討內部人股票交易與盈餘管理之關聯性，並進一步檢視我國近年來為強化公司治理所引進之獨立董監事制度是否能對內部人交易與盈餘管理間之關聯性產生抑制效果。在分析時，本研究係將全部樣本區分為賣出組及買入組，並分別進行驗證。 實證結果顯示，發生內部人異常出售股票交易之樣本公司，其管理階層將於同一期進行使盈餘降低之盈餘管理。而此一結果所隱含之意義為，內部人為降低日後回補持股之成本，會於出售持股當期進行盈餘之操弄，以求影響未來股價。然而，在發生內部人異常買入股票現象之樣本公司，卻未發現如本研究所預期之內部人為極大化未來出售持股利益而從事使盈餘提高之盈餘管理的現象，本研究推測可能原因係內部人買入本公司股票之理由眾多，因此也不必然有拉抬未來股價以求自未來出售股票交易中獲利之考量。 另外，在獨立董事與獨立監察人對於內部人異常交易及盈餘管理間關係之抑制效果的部分，在買入組或賣出組均未發現顯著之抑制效果。對此，本研究認為可能之原因係獨立董監事制度在我國實施之時間尚短，且多數公司係基於法令之要求始設置獨立董監事，而在這樣的現況下，似乎難以預期獨立董監事能有效監督公司內部人之異常股票交易行為以及盈餘管理行為。 / This thesis examines if there is an association between insider trading and earnings management. Furthermore, this thesis examines whether independent directors and independent supervisors can suppress the relationship between insider trading and earnings management. In the analytical process, the whole sample is divided into two sub samples which are sell and buy sub sample. The two sub samples are examined separately. And this thesis finds that there is a negative association between insider trading and earnings management in the sell sub sample which suggests that executives will manage earnings downward in the same period of insider selling to minimize their cost of buying stocks back in the future. And this result is consistent with the hypothesis. But no proper evidence is found about the relationship between insider trading and earning management in the buy sub sample. This may result from that there are many reasons for insiders to buy stocks of their firms. And insiders do not necessarily buy stocks of their firms to make profits by selling them in the future. Besides, in the part of the suppressing effect of independent directors and supervisors, proper evidences do not exist neither in the buy sub sample nor in the sell sub sample. A possible reason is that since the independent directors and supervisors system is still new in Taiwan, and most firms with independent directors and supervisors are just enforced by regulations to set independent directors and supervisors, it's hard to expect that independent directors and supervisors to play their roles effectively.

本研究探討私募折價幅度及私募前後績效之影響因素，並將應募人分為內部人、積極投資人以及消極投資人三種，觀察不同應募人下的私募，其私募前及私募後是否有累計異常報酬。 實證結果發現，在私募前股價表現與私募對象之關係方面，當私募對象為內部人時，在私募前45日股價即開始下挫，之後的累計異常報酬皆為負值，其原因可能為內部人藉由套利交易，先行在集中市場上賣出手中原有持股，再用較低價格認購私募新股，此舉不但能使手中持股的成本降低同時也能維持既有股權。關於私募半年後的股價表現，內部人及積極投資人私募後的累計異常報酬顯著為正，代表內部人在投資私募新股時，可能隱含著未來公司有較好的投資機會；至於積極投資人後續績效為正，可能代表積極投資人未來將會扮演監督者的角色，有助於提高公司的價值。迴歸分析也顯示，當公司私募的價格相對於公司在私募定價日當時的股價折價越多時，私募之後的累計異常報酬越低，代表私募折價會降低公司價值，傷害現有股東的權益。 / This study investigates the effect of private placements on stockholder wealth before/after the events based on cumulative abnormal return for three categories of investors, namely, the insiders, active investors and passive investors. For private placements with insider investors, significant negative abnormal return prior to private placements may reveal sell arbitrage taken by insiders while significant positive abnormal return subsequent to private placements supports signaling theory. Evidence showing significant negative relation between price discount on private placements and subsequent business performance implies the price discount reduces market value and hence harmful to existing shareholders’ wealth.

Abstract Based on the sequential auction model of Kyle (1985) and embedded the formulation of positive feedback traders in De Long et al. (1990), our model formulates a recursive market game of insiders, noise traders, and market makers. In particular, the submitted demands of positive feedback inertial traders are influenced by previous own trading quantities. I prove the existence and uniqueness of a recursive linear equilibrium with positive feedback inertial trades. Further, the equilibrium calibrates that the strategies of insider and market makers are also influenced by positive feedback trades. Finally, we conduct a simulation analysis to get a price-volume pattern with some empirical interesting implications. Finally, this thesis takes trading strategies to trade the individual stock in TSEC. Although the market mechanism of TSEC has no market makers, it is still expected that these trading strategies are useful for traders which implies the information is filtrated by these trading strategies.