Univrsity Of Tehran Press Accounting and Auditing Review 2645-8020 23 3 2016 11 21 Investigating the impact of Mandatory Audit Firm Rotation on Audit Fee and Audit Market Competition Investigating the impact of Mandatory Audit Firm Rotation on Audit Fee and Audit Market Competition 333 352 59779 10.22059/acctgrev.2016.59779 FA Yahya Hassas Yeganeh Farokh Barzideh Mohammad Taghi Taghavifard Muhammad Farahmand Seyed Abadi Journal Article 2016 04 05 This study aims at investigating the impacts of Mandatory Audit Firm Rotation (MAFR) on audit fees and audit market compeition among firms listed on Tehran Stock Exchange (TSE). Since 2007 firms listed on TSE are not allowed to use services of any single audit firm for more than 4 consecutive years. We tested our hypotheses using multivariate regression analysis and mean comparison test. Our sample consists of 95 firms listed on TSE during the period 2006-2014. Our results, in summary, revealed that MAFR has cuased a significant increase in audit fees, more than the usual additional fees charged in first year audit in voluntarily audit firm rotations; and, therefore has imposed additional audit costs to firms. Also, there were no statistically significant changes in market share of high-quality renked audit firms and those of lower quality ranks, before and after imposition of MARF rule in Iran. This study aims at investigating the impacts of Mandatory Audit Firm Rotation (MAFR) on audit fees and audit market compeition among firms listed on Tehran Stock Exchange (TSE). Since 2007 firms listed on TSE are not allowed to use services of any single audit firm for more than 4 consecutive years. We tested our hypotheses using multivariate regression analysis and mean comparison test. Our sample consists of 95 firms listed on TSE during the period 2006-2014. Our results, in summary, revealed that MAFR has cuased a significant increase in audit fees, more than the usual additional fees charged in first year audit in voluntarily audit firm rotations; and, therefore has imposed additional audit costs to firms. Also, there were no statistically significant changes in market share of high-quality renked audit firms and those of lower quality ranks, before and after imposition of MARF rule in Iran. https://acctgrev.ut.ac.ir/article_59779_4b63425d1d5c077a2bb63151ee5a7f35.pdf