營運資金管理與裁決性應計數之估計

Working Capital Management and Estimations of Discretionary Accruals

本研究探討營運資金管理對採用Jones模型估計裁決性應計數之影響，並分析此影響對盈餘管理研究之意涵。當公司有營運需求而調整營運資金時，通常也涉及應計數調整；此種調整係屬正常營運決策，與盈餘管理行為有別。本研究以員工人數變動率衡量營運資金管理程度，依其大小將樣本區分為四組；實證發現，最高（低）組公司之裁決性應計數顯著大（小）於其他公司，且裁決性應計數大（小）於零之模擬測試有過度拒絕現象，顯示裁決性應計數存在估計偏誤。本研究進一步檢視現金增資公司及彌補虧損減資公司是否有明顯之裁決性應計數，發現在考量營運資金管理程度後，過去文獻宣稱該等公司有明顯盈餘管理之現象並不存在。

This study investigated the effect of working capital management on estimated discretionary accruals and discussed the implications of this effect for future research on earnings management. Generally, a firm adjusts its working capital investment when a discrepancy exists between working capital and actual operational needs. This type of working capital management is regarded as a normal operating strategy, which means that the accruals resulting from using this strategy should be normal accruals, not discretionary accruals. This study measured the level of working capital management by the growth rate of the number of employees. Based on the level of working capital management, this study divided the entire sample into four equal-sized groups. Our results indicate that the discretionary accruals of first (fourth) quartile firms are significantly greater (smaller) than those of other firms. The results of simulation tests in which the null hypothesis of zero abnormal accruals was rejected were beyond normal rejection rate, indicating that estimation bias existed in the discretionary accruals of the sample firms. The estimation bias in discretionary accruals affected the results of further empirical study on whether firms that issued seasoned equity offerings or reduced capital to settle accumulated losses manipulated earnings.