隨著全球化趨勢與工商業的發展，多角化活動普遍存在於企業的投資策略當中。然而，多角化同時為公司帶來效益與成本，且過去關於多角化對公司價值影響之研究則有許多學者提出不同的看法。而在多角化帶給公司的成本中，有一類型是因為多角化經營使公司的整體結構與營業項目變得更加錯綜複雜，導致代理成本增加。因此，本文將以代理理論為基礎，針對以下兩個主題進行探討。第一個為多角化對審計品質之影響，探討多角化公司在面臨較嚴重的代理問題時，是否會尋求高品質會計師的審計服務來降低與股東間的資訊不對稱程度進而減少代理成本。而第二個則是審計品質對多角化超額價值之影響，探討多角化公司雇用高品質會計師是否確實有利於公司價值。根據本研究實證結果發現，多角化與審計品質顯著正相關，且多角化公司雇用高審計品質會計師事務所有利於公司價值。 This study examines how the extent of diversification influence audit quality and the moderating role of audit quality on the excess value attributed to diversification. An explicit distinction is made between international and industry diversification. The empirical evidence reveals that the extent of both international diversification and industry diversification are positively related to the likelihood to appoint high-quality auditors. Further, firms appointing high-quality auditor suffer less diversification discount attributed to diversification. Overall, our results are consistent with the conjecture that high-quality auditor is an effective mechanism to reduce agency costs arising from diversification.
