由於公司內部人與投資人之間普遍存在資訊不對稱，故內部人經常得以在 特定事件宣告前即獲悉相關資訊，並藉此優勢資訊買賣證券，獲取不當利益或規 避損失。此外，當經理人意圖出售公司持股時，甚至可能利用裁量性應計項目， 調整當期盈餘，進而影響股價。本研究計畫旨在探討內部人交易與盈餘管理的關 聯性，並檢測公司治理機制對於因內部人交易動機而引發的盈餘操縱之抑制效 果，以及公司治理對內線交易行為的監督效果。 本研究計畫採兩階段進行，第一階段先以兩階段最小平方法(Two-stage Least Square)檢測內部人交易與盈餘管理間的因果關係；其次，檢視公司治理機 制能否有效減緩經理人為買賣持股而從事的盈餘操縱，本研究尚擬建立公司治理 指標，期使投資大眾及金融監理單位能藉此衡量公司治理機制對內部人交易的監 督效果。第二階段則根據被起訴的內線交易案件建立內線交易資料庫，並利用羅 吉斯迴歸(Logistic Regression)進一步檢測公司治理變數對內線交易行為的監督 效果。本研究期能藉由實證結果獲致有效偵測內線交易之公司治理變數，以提供 投資人決策分析之參考，並協助金融監理單位監督股市運作，消弭投資人與內部 人間資訊不對稱之問題。 Due to the prevailing information asymmetry between corporate insiders and investors, insiders can take the advantage of privileged information about important events to reap profits or avoid losses on the stock market. Moreover, the management may adjust discretionary accruals to raise current earnings and, therefore, boost stock prices before they intend to sell their holdings in the subsequent period. This study aims to explore the association between insider trading and earnings management, to examine the moderate effect of corporate governance on earnings manipulation induced by managers’planned trading, and to investigate whether corporate governance can even constrain illegal insider trading effectively. This project consists of a two-phase research agenda to address above issues. In the first phase, this study employs a two-stage least square regression to examine the plausible causal relationship between insider trading and their behavior on earnings management, and furthermore, to investigate whether corporate governance can mitigate such earnings management prior to insider trading. This study also attempts to construct a corporate governance index to assist investors and Financial Supervisory Commission (FSC) in assessing the monitoring effect of corporate governance on insider trading. In the second phase, a database of illegal insider trading will be collected from criminal prosecution of insider trading cases by the Department of Justice. Finally, a logistic regression is applied to explore the moderate effect of governance variables on illegal insider trading. Hopefully, the empirical findings may be applied to alleviate the agency problem due to asymmetric information between investors and insiders.