會計師法律責任提升對大型會計師事務所客戶篩選之實證研究

Abstract

近年來，國內外舞弊案件頻傳，社會大眾對於會計師法律責任逐漸重視，主管機關對於會計師之管制與懲處也趨於嚴格，負責為投資人提起團體訴訟與仲裁求償的機構—投資人保護中心亦於民國92年成立，會計師面臨的訴訟風險與法律責任與日俱增。為了在會計師法律責任日益提升的環境追求自保，我國大型會計師事務所開始注重客戶篩選的機制，陸續於近年成立承接客戶之審核小組，負責事務所簽證業務之審核與風險管理、評估與客戶之間的獨立性、進行客戶誠信正直之檢查等任務。 為驗證會計師法律責任提升將影響大型會計師事務所客戶篩選之標準，本研究將我國會計師法律責任區分三個時期，恩隆案發生前(1999~2001)、恩隆案發生後至博達案發生前(2002~2003)以及博達案發生後(2004~2006)，愈後面之時期代表會計師法律責任愈高。關於會計師事務所承接客戶篩選標準之衡量，本研究將焦點放置於簽證客戶財務風險的構面上，利用Choi et al. (2004)對於簽證客戶之分類方式，將上市(櫃)公司區分為「大型會計師事務所繼續承接之客戶」、「大型會計師事務所新承接之客戶」、「大型會計師事務所未繼續承接之客戶」以及「持續非由大型會計師事務所承接之客戶」四大類，來檢驗我國不同類別之簽證客戶的差異以及跨時期簽證客戶財務風險之差異。 本研究利用差異檢定以及參考Choi et al. (2004)所設定的線性多元迴歸模型，來檢驗不同類別之簽證客戶財務風險的差異以及跨時期簽證客戶財務風險之差異，本研究亦參考Jones and Raghunandan (1998)所設定的Logistics迴歸模型，來檢驗會計師法律責任趨嚴，是否會影響大型會計師事務所對於客戶財務風險之篩選標準；最後本研究利用比例分析檢驗「大型會計師事務所於高風險客戶市場之占有率」與「高風險客戶占大型事務所客戶之比重」跨時期比例之差異。 實證結果顯示，當會計師較有法律責任之考量時，大型會計師事務所傾向不承接財務風險偏高之客戶，並且當簽證客戶之財務風險惡化時，將不願繼續承接該客戶。我國近幾年接連發生重大的舞弊案件，會計師法律責任大幅提升，訴訟風險也連帶地提高，因此大型會計師事務所將提升客戶篩選標準作為因應，使得其所承接與繼續承接之客戶在財務表現上，較會計師法律責任提升前所承接或繼續承接之客戶為佳；且承接之客戶在財務表現上較優於非大型會計師事務所之客戶；對於財務風險偏高之客戶，承接比例也較為降低。

In recent years, corporate fraud incurred in succession leads to the public emphasizing the duty of CPA, and leads to the regulations on auditor’s responsibility getting servere. Moreover, because the Securities and Futures Investors Protection Center, who brings lawsuits and asks arbitration in behalf of investors, was established in 2003, the litigation risk faced by auditors is steadily on the increase. In order to survive on the growing legal liabilities, big CPA firms start emphasizing client selection, and set up client acceptance reviewing group taking charge of risk management, assessments of independence and management integrity. To verify the growing audit liability will lead to large audit firms increasing client selection standards, this study divides recent years into 3 periods by the extent of audit liability exposure: Pre-Enron period (1999~2001), Post-Enron period (2002~2003), and Post- Procomp period (2004~2006). Regarding to the measurement of client selection standard, this study focuses on client’s financial risk and refers to the clients classification mothod used by Choi et al. (2004) partitioning listing companys into four categories: continuing big 4 clients, new big 4 clients, departing big 4 clients, and continuing non-big 4 clients. This study uses two-sample t test and wilcoxon signed rank sum test and refers to linear multi-regression model used by choi et al. (2004) to examine the difference between different periods and different kinds of clients. This study also refers to logistics regression model used by Jones and Raghunandan (1998) to test the impact on large audit firm client selection. Beside, this study utilizes probability test to examine the changes in the propotion of high risk clients accepted by large audit firms. The empirical analysis results suggest that large audit firms incline not to supply audit service to the public companies which are perceived as high risk, when there is higher concern over legal liability. If client’s financial condition is turning into worse the large audit firms won’t continuously retain that client. This study also provides evidence that because of increasing litigation costs in recent years large audit firms raise its client selection standard in clients’ financial condition.