近來遠航爆發弊案後,公司操縱盈餘以虛飾財務報表之問題日益受到重視,過去探討公司治理與盈餘管理的文獻相當廣泛,然而甚少文獻探討不同負債比率下,董事會特性與盈餘管理之關係。因此本文以探討我國上市公司之董事會特性在不同負債比率對盈餘管理之影響,是越具有監督效果?或者造成反效果,使得管理者更易從事盈餘管理?本研究對象為1997年至2007年兼具時間序列及橫斷面之平衡式縱橫資料(balanced panel data)共277家台灣上市公司,並且採用Gonzalez, Terasvirta and Dijk (2004,2005)所發展的縱橫門檻平滑移轉迴歸模型(Panel Smooth Transition Regression Model,PSTR)。 本研究之實證結果顯示,負債比率存有兩個門檻,其比率分別為29.6%及33.4%,本文依據門檻值將樣本分成低負債(小於等於29.56%)、中負債(介於29.56%與33.4%)與高負債(大於33.4%)公司。(一)在低負債公司,管理者持股比率、董事會規模及外部董事席次比率與盈餘管理無關。(二)在中負債公司,管理者持股比率與盈餘管理呈負相關,管理者沒有違約風險及高利息成本壓力,且管理者擁有足夠股權時,符合利益一致假說(convergence of interest hypothesis) ,將會以公司利益最大化為前提,管理者較不會從事盈餘管理;在高負債公司,管理者持股比率與盈餘管理呈正相關,管理者為擔心違反負債契約,較有動機從事盈餘管理,以達到債權人所要求之盈餘。(三)無論中負債公司或高負債公司,董事會規模與盈餘管理皆呈負相關,表示董事會規模越大,越不會從事盈餘管理,尤其在中負債公司,更能有效地發揮監督機制,抑制管理者從事盈餘管理。(四)無論是低、中或高負債公司之外部董事席次比率與盈餘管理無關。
Recently after the burst of Far Eastern Airline fraud case, the problem that companies manipulating earnings to prettify financial statements has drawn increasing concerns as days go by. In the past literatures that explore corporate governance and earnings management are rather extensive, but few has explored the correlation between the characteristics of the board of directors and earnings management under different debt ratio, which is the purpose of this study. Results of this study show that: (1)In low liabilities companies (with debt ratio of less than or equal to 29.56%), management ownership interest, size of the board of directors and numbers of outside directors are not correlated to earnings management. (2)In medium liabilities companies (with debt ratio between 29.56% and 33.4%), managers do not have default risk or pressure of high interest cost and when managers has enough ownership interest, as in consistency with the convergence of interest hypothesis, they are less likely to engage in earnings management. In high liabilities companies (with debt ratio of greater than33.4%), managers tend to worry about breach of debt contract and therefore are more motivated to engage in earnings management in order to achieve the earnings required by creditors. (3) Regardless of being a medium or high liabilities company, as the size of the board gets larger, companies are less likely to engage in earnings management. Especially in medium liabilities companies, a large size board of directors can exert supervising mechanism more effectively, inhibiting managers to engage in earnings management. (4) Regardless of being a low, medium or high liabilities company, the numbers of outside directors are not correlated to earnings management.