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    Did the PCAOB’s Restrictions on Auditors’ Tax Services Imp...
    research summary posted September 13, 2016 by Jennifer M Mueller-Phillips, tagged 01.0 Standard Setting, 01.06 Impact of PCAOB, 04.0 Independence and Ethics, 04.03 Non-Audit Services 
    Did the PCAOB’s Restrictions on Auditors’ Tax Services Improve Audit Quality?
    Practical Implications:

     This study serves the purpose of examining the PCAOB’s role as overseer of public company auditing, while separating from previous studies by targeting the PCAOB’s restrictions on auditors’ tax services, which have not been examined in the past. This study also examines whether APTS pose a threat to audit quality but again differentiates itself from previous literature by focusing on only the tax services that the PCAOB chose to ban and by utilizing the difference-in-differences design to address the limitation of the cross-sectional approach utilized by other studies in the past. After reviewing these findings, it is possible that the PCAOB restrictions did not fully accomplish their objective.


     Lennox, C. S. 2016. Did the PCAOB’s Restrictions on Auditors’ Tax Services Improve Audit Quality? The Accounting Review 91 (5): 1493-1512.

    PCAOB, audit quality, and auditors’ tax services.
    Purpose of the Study:

    In 2005, the Permanent Subcommittee on Investigations of the U.S. Senate reported that audit firms were selling potentially abusive or illegal tax-planning strategies to audit clients and their top executives on a contingent fee basis. This concerned regulators for many reasons; consequently, the PCAOB adopted three new rules to address these potential threats to audit quality. First, Rule 3521 reaffirms the ban on contingent fees that existed under Rule 302 of the American Institute of Certified Public Accountants’ Code of Professional Conduct. Second, Rule 3522 bars audit firms from selling aggressive tax services to audit clients. Finally, Rule 3523 forbids audit firms from selling tax services to executives in a financial reporting role. These three rules became effective from October 31, 2006 onward. The PCAOB stated that the rules were intended to improve audit quality, and, by extension, the quality of financial reporting. The purpose of this study is to test whether the restrictions met this objective.

    Design/Method/ Approach:

    Because audit quality is not directly observable the author focuses on accounting misstatements, both misstatements that are tax-related and other types, and the issuance of going-concern opinions. The author separates companies into groups based upon the reduction of APTS purchases between July 26, 2005 and October 31, 2006. He then compares the differences in misstatements and going-concern opinions between the treatment and control groups and tests whether these differences change after the PCAOB imposed the restrictions on auditors’ tax services. 

    • The author finds that in the period before the restrictions, there is no difference in the incidence of going-concern opinions between the treatment and control companies; however, the treatment companies are more likely than the control companies to have accounting misstatements and tax-related misstatements. This supports the premise of regulators that the treatment companies had lower-quality auditing before the restrictions were introduced. 
    • The author finds no significant changes in misstatements, tax-related misstatements, or going-concern opinions subsequent to the APTS restrictions after using a difference-in-differences research design. In fact, the treatment companies continue to have significantly more accounting misstatements and more tax-related misstatements in the period subsequent to the APTS restrictions.
    • The author finds large and highly significant reductions in APTS fees when the restrictions were introduced. 
    Independence & Ethics, Standard Setting
    Impact of PCAOB, Non-audit Services