審計委員會會計專家與財稅差異之關聯性研究

Abstract

本研究主要探討審計委員會之設置與審計委員會會計專家數量對於財稅差異之影響。財稅差異係源自於財會準則與稅法規範不同所導致，而近年來公司財稅差異有逐漸擴大之跡象，過往學術研究將財稅差異之形成原因歸咎於企業盈餘管理行為，認為管理階層可以透過會計準則較為彈性之特點，選擇最有利於企業的會計方法來操縱盈餘，但此情況並不影響課稅所得而因此產生財稅差異。審計委員會的設立目的是為了加強公司治理機制，並透過會計專家之專業性，使財務報表之虛擬交易、非常規關係人交易等操縱手法更容易被察覺，因此本研究預期我國已設置審計委員會之公司有較小的財稅差異，且審計委員會會計專家數量與財稅差異為負相關。 本研究以2008年至2012年我國有設置審計委員會之上市櫃公司為對象，運用財務報表所得稅相關資料推估財稅差異，課稅所得的推估參照Manzon and Plesko(2002)的計算式，會計專家的認定方式則採用DeFond et al.(2005)之研究。 實證結果發現，設置審計委員會之公司，比相似規模、相同產業但未設置審計委員會之公司有較小的財稅差異，然而會計專家數量佔審計委員會成員比例與財稅差異為正相關但不具統計上的顯著性。本文認為審計委員會會計專家無法減少財稅差異之原因可能是由於我國獨立董事同時扮演監督與顧問的角色所致，除了監督財務報表之製作外，還給予租稅規劃方面上的建議。

This thesis investigates the effect of the audit committee establishment and the number of accounting experts on book-tax differences. Book-tax differences may result from the different purposes between the financial reporting standards and tax rules or result from earnings management. This study predicts that firms with audit committees will have less book-tax differences, and firms with the number of accounting experts will have less book-tax differences. Using the listed companies with an audit committee during years 2008 to 2012, I find that firms with audit committee have less book-tax differences than firms without audit committee. However, I did not find that firms with the number of accounting experts in an audit committee have less book-tax differences. The potential explanations may be due to the fact that independent directors serve dual roles both as a monitor of management regarding financial reporting and a consulting advisor regarding tax planning.