財稅差異與盈餘管理之關聯性研究

The Relationship between Book-Tax Difference and Earnings Management

本研究旨在探討企業財務會計所得與課稅所得差異（以下簡稱財稅差異）與盈餘管理之間的關聯性。有別於過去盈餘管理及財稅差異之研究；本研究從上市公司的財務報告書中，整理出公司財稅差異的實際資料，探討財稅差異背後是否隱含著企業盈餘管理行為，可作為偵測企業盈餘管理的指標。本研究選擇兩種企業最常見的盈餘管理行為，分別為：避免盈餘下降以及避免盈餘報導損失加以驗證，以建立企業盈餘管理行為與財稅差異之關聯性。實證結果顯示，財稅差異在偵測公司上述兩項盈餘管理行為時，均有顯著的解釋力；若進一步將財稅差異區分成裁量性與非裁量性的成分後發現，裁量性的財稅差異，在偵測公司之盈餘管理行為上，亦具有解釋力。最後，本研究還將過去文獻認為能偵測公司盈餘管理行為的所得稅相關指標與財稅差異一同比較，發現財稅差異在偵測上述兩種盈餘管理行為上，均優於裁量性的財稅差異、暫時性差異以及第四季有效稅率的變動。

The main purpose of this article is to analyze the relationship between book-tax difference and earnings management. Different from prior research, this study organizes and analyzes the actual data of book-tax difference from listed companies’ Annual Financial Reports of Market Observation Post System, and further uses book-tax difference as a proxy to discuss whether it can detect the behavior of earnings management to meet or slightly beat two earnings targets: (1) to avoid reporting an earnings decline, (2) to avoid reporting a loss. The results show that book-tax difference is incrementally useful in detecting both earnings management behaviors. Then, after dividing the book-tax difference into discretionary and non-discretionary components, it was found that discretionary book-tax difference still has incremental usefulness in detecting earnings management behaviors. Finally, when compared book-tax difference with other tax related index which prior research believed could be used to detect earnings management, it was found that the earnings management detective power of book-tax difference is superior to the discretionary.