本研究旨在探討強制性輪調下，大型會計師事務所會計師更換之組別型態對於控制股東控制權偏離與質押持股所可能誘發盈餘管理行為的抑制效果是否具有明顯之差異。希冀藉由控制股東核心代理問題的分析，比較不同組別型態會計師更換之審計品質，瞭解強制輪調後實際之審計品質狀況，並據以提出輪調政策具有價值之參考配套措施。本研究以台灣四大會計師事務所查核的上市櫃公司為研究對象，研究期間自2003年至2009年，自國內四大會計師事務所取得組別資料，並運用傾向分數配對法（propensity score matching method），控制會計師更換組別型態內生性特徵，以分離公司對會計師更換可能存在自我選擇之偏誤，至於盈餘管理衡量方式則爰用裁決性應計數。研究結果顯示，在強制性輪調制度下，組間更換之會計師相較於組內更換之會計師更能抑制控制股東控制權偏離所產生的盈餘管理行為，即使考量董事獨立性，實證結果也未有改變。本研究政策意涵為，針對控制權偏離明顯之集團企業，若能要求會計師事務所配合進行組間會計師更換，將有助於提升審計品質，降低控制股東盈餘管理之機會。另一方面，本研究並未發現組間更換之會計師對於控制股東質押持股盈餘管理抑制效果優於組內更換之會計師，反倒發現控制股東質押比率愈高，組間更換之會計師審計行為有趨於審慎之傾向，故相對於組內更換之會計師愈會容忍使用調降盈餘之應計數。 This study explore whether there are distinct differences between the profit management control effect on the control deviation of control shareholders and pledge shares or not, which are triggered by the intra-groups and inter-groups auditor rotation in big accounting firms under the coercive rotation. Hoping to comprehend the practical audit quality after the mandatory rotation and present some valuable reference supplementary for rotation policy, by analysing on the controlled shareholders core agent problem and comparing the audit quality among different group-types of accountant rotation. This research targets on the public companies audited by the Big Four in Taiwan from 2003 to 2009. The group data are collected from the Big Four, and via the propensity score matching method to control the endogenous of the intra-group and inter-group accountant rotation, so as to separate the potential self-selection bias on accountant rotation for organizations. When it comes to profit management, the discretionary accrual helps to analysis.The finding demonstrates that the inter-group rotation outweighs the intra-rotation on restraining the profit managing behavior from control deviation of controlling shareholders under the coercive rotation, there is nothing different even on the consideration of the independence of directors. The implication is that it helps for enhancing the audit quality and reducing the opportunity of profit control on the control shareholders by demanding the inter-group accountant rotation. On the other hand, there is no evidence demonstrates the performance of retraining on controlling stockholders’ pledge shares of inter-group accountant rotation better-performs than intra-group rotation. Instead, the higher ratio of restraining pledge share it is, the more cautious and more careful on audit behavior on inter-group rotation would be. Therefore, compare to intra-group rotation, accountants prefer exercising on reducing on profit discretionary accrual.
