會計文獻指出公司管理者從事實質盈餘管理時，其動機可區分為投機性及非投機性兩類型，本研究預期不同動機之實質盈餘管理對公司後續會計績效的影響應有顯著差異。本文以非平衡性追蹤資料為實證模型，探討公司治理在實質盈餘管理決策中所扮演的角色，透過公司治理觀點以釐清目前實證文獻中，實質盈餘管理對公司後續會計績效影響之不一致的現象。實證結果顯示：平均而言，公司實質盈餘管理行為對後續會計績效有負面影響，在某種程度支持實質盈餘管理投機性假說。然納入公司治理變數後，發現公司治理愈佳者，可有效降低實質盈餘管理之負面影響，而獲致相對較佳的後續會計績效。換言之，當公司治理愈佳時，管理者會謹慎評估使用實質盈餘管理所帶來之成本收益以避免損害公司中長期績效，而存在非投機性實質盈餘管理可能性。進一步分析顯示，在博達案發生之後，非投機性實質盈餘管理對後續會計績效之效果更為明顯。

Prior studies suggest that there are two motivations for managers' real earnings management, i.e., opportunism versus non-opportunism hypotheses. In light of the findings, this study argues that the two types of real activity earnings management can affect future accounting performance differently. Using unbalanced-panel data, this study examines the moderating role of corporate governance in managerial real earnings management and attempts to address the conflicting evidence about the effect of such behavior on subsequent accounting performance. The result shows that, on average, real earnings management is negatively associated with subsequent accounting performance, supporting the opportunism hypothesis. However, firms with better corporate governance can mitigate this negative relationship and generate higher future accounting performance. In other words, managers of firms with better corporate governance cautiously consider the tradeoffs between the costs and benefits of real earnings management to ensure that the decision would not sacrifice long-term performance, which is in line with the non-opportunistic motivation of real earnings management for firms with better corporate governance. Further analyses show the findings are more pronounced after the PROCOMP scandal.