過去文獻通常採用全國觀點予以衡量競爭，隱含各地審計市場具有相同的結構，然而，在台灣，多數會計師事務所僅在其座落處與鄰近地區從事競爭，所以各地審計市場或許會因不同競爭者從事競爭而有不同之市場結構，因此，本研究嘗試利用區域觀點予以測量競爭，再加上，外在競爭環境究竟會對會計師產業之績效有何影響，在執業環境愈趨嚴峻與艱困下，對會計界內外決策制定者而言，是值得深思與探討之課題，有鑑於此，本研究旨在以區域觀點為基礎探討審計市場競爭對會計師產業績效之關聯性。本研究之實證結果顯示，會計師事務所在愈具競爭性之地區執行業務，其效率愈佳，意謂著競爭能促使會計師事務所提昇效率。本研究冀能補充過去相關文獻之不足，以及其結果能供會計界內外決策者作為相關決策之參考依據。

Prior studies have often measured audit market competition from a national perspective, which implies that all regional audit markets have same structures. In Taiwan, however, most public accounting firms only compete in neighboring regions and areas where they are located; local audit markets may be structured differently due to the different competitors involved. This paper attempted to measure audit market competition from a local perspective. In addition, how external competitive environment affects the performance of a public accounting firm is believed to be of crucial importance to decision makers within and outside the accounting profession, especially when operating environment for auditors is becoming increasingly difficult. In light of these, I examine competition within the audit market from a local perspective, and investigate its relation with the performance of public accounting firms. The empirical results show that public accounting firms tend to have higher efficiencies when practicing in more competitive regions. These results suggest that competition provides incentives for public accounting firms to improve and raise efficiency. This study fills in the gaps of prior studies. And conclusions of our research may provide useful references for decision makers in policy making, both within and outside the accounting profession.