會計師輪調制度在臺灣實行多年，本研究欲探討輪調制度之實行是否會影響企業委任會計師事務所或會計師之選擇，且將企業所屬產業環境競爭程度納入考量。本研究以台灣上市櫃企業為觀察對象，研究期間為1991年至2014年，首先針對輪調制度實施前後，探討企業之產業環境競爭程度高低，對於會計師事務所或會計師選任之差異，結果顯示輪調制度實施前，企業之產業環境競爭程度越高，越不會選擇產業專精度高之會計師，可能原因為會計師可透過長任期，累積對客戶及其所屬產業之瞭解，以提升審計品質，或是企業為防止營業秘密經由查核外流所致；但輪調制度實施後，面對會計師需定期輪調，產業環境競爭程度高之企業會對高品質會計師事務所(或會計師)產生需求，代表在有限任期之規定下，企業為提供高品質之財報予投資人，會有不同之考量；本研究進一步探討企業委任會計師事務所或會計師之選擇是否影響審計品質，研究結果發現，於輪調制度實施後，產業環境競爭程度高之企業，若選擇由非產業專家事務所或會計師查核，其審計品質會有下降之現象。 Mandatory auditor rotation has existed in Taiwan for many years. This study discusses whether the rotation system and industry competition influence the choice of auditor or CPA firm. Studying listed firms during the period of 1991 to 2014, we researched the impact of industry competition on auditor choice before and after the implementation of the rotation system. Results showed that prior to mandatory rotation, greater industry competition meant that firms were less likely to engage auditors with high levels of industry specialization. This may be due to concerns that auditors who had worked in the same industry for a long period of time could develop a more in-depth understanding of their clients that would enhance their audit quality. Or, companies may have been primarily concerned about the possibility of trade secrets being leaked by seasoned industry auditors. After mandatory rotation came into practice, however, companies in highly competitive industries sought out quality CPA firms (or auditors). This indicates that once auditor tenure was limited, companies were more concerned with providing quality financials to their investors. We also examined whether the choice of auditor or CPA firm affects audit quality. Results showed that after implementation of mandatory rotation, companies in highly competitive industries who chose firms or auditors with no industry expertise experienced poorer audit quality.
