審計客戶重要性與股價暴跌風險：以經濟動機與情感依賴衡量

Abstract

本文探討客戶重要性對審計獨立性之影響，使用股價暴跌風險作為審計獨立 性經濟後果的代理變數。研究推論若會計師因經濟或情感依賴，將接受企業較為激 進的會計表述，較低的審計品質會延誤企業揭露壞消息，因而提高股票暴跌風險。 本研究使用揭露簽證會計師姓名的台灣資料，以衡量會計師個人層級的客戶重要 性。非四大審計事務所主簽會計師的經濟客戶重要性與公司股價暴跌風險呈現倒 U型非線性關係，此結果代表會計師對於具經濟重要的客戶，會犧牲其審計獨立性， 但當客戶經濟重要性超過特定程度後，其審計作業又更加嚴格。四大事務所的副簽 會計師對具經濟重要性的客戶較為保守，但對於情感上具有重要性的客戶又較為 積極，因為研究結果顯示前者(後者)有較低(較高)的股票暴跌風險。額外分析發現 主簽會計師的審計經驗可以減輕主簽會計師經濟依賴帶來的負面影響，但副簽會 計師的審計經驗有相反的結果。未來研究應探索主、副簽證會計師的差異。

This paper examines the impact of client importance on auditor independence, using stock price crash risk as a proxy for the economic consequences of auditor independence. It expects that audit partners reduce audit quality and accept aggressive accounting choices for their important clients due to economic or emotional dependence. In addition, poor audit quality delays companies’ release of bad news and therefore increases their stock price crash risk. I measure audit client importance at the individual partner level, using Taiwan data where engagement partners must disclose their names. I find an inverted U-shaped curvilinear relationship between economic client importance and stock price crash risk for lead auditors in the full sample and non-Big4 subsample. The results imply that auditors sacrifice independence for economically important clients but conduct strict audits when economic client importance exceeds a certain level. Concurring auditors in the Big4 subsample are more conservative toward economically important clients, but more aggressive for emotionally important clients, as my results show lower (higher) stock price cash risk for the former (latter). In additional analyses, I find the audit experiences of lead auditors mitigates the adverse effect of lead auditors’ economic dependence, but that of concurring auditors present contrary results. Further research is warranted to explore the differences between lead and concurring auditors.