本文旨在探討審計品質對公司績效與資金成本關係之影響。不同與以往文獻僅探討負債或權益資金成本,本文研究審計品質對改良式杜邦之績效和負債與權益資金成本之影響。研究觀測值為1993年至2010年1210家上市櫃公司。實證結果發現,前期公司績效較好,當期權益資金成本會較低。而當期選擇大型事務所簽證的公司,其下期淨營運資產報酬率會較好;當期異常應計數與下期淨營運資產報酬率、下期資產週轉變動呈顯著反向關係,亦即當期審計品質較佳,下期公司績效會較好。最後,加入異常應計數與未加入時相較,雖前期公司績效與當期權益資金成本一樣呈顯著負相關,但績效對權益成本的負向影響減少,表示審計品質可減輕前期公司績效對權益資金成本的影響。因此,研究結果建議企業在決策如何降低權益資金成本,考慮公司績效當然重要,但審計品質也是不可忽略的關鍵因素。
This paper explores the effects of audit quality on the relationship between performance of firm and costs of capital. Contrary to prior literature simply studies equity or liability cost of capital, this study employs the modified DuPont analysis as performance indicators and focuses on both equity as well as liability costs. The sample includes 1,120 firms listed in Taiwan Stock Exchange and OTC from 1993 to 2010. The results reveal that prior performance of firm has a significantly negative effect on equity cost. Audit quality has a significantly negative effect on next period performance of firm. Finally, no matter whether include discretionary accruals to explain the relationship between performance of firm and costs of capital or not, performance of firm has a significantly negative effect on equity cost of capital, while audit quality lessen the negative impact of performance on cost of equity. Therefore, the finding suggests that when firms try to reduce equity cost, managers should consider not only performance of firm but also audit quality.