This thesis is motivated by reported instances of opportunistic aggressive tax positions taken by large corporations across the globe. The role of professional service providers in delivering various types of tax services, especially the role of accounting firms which provide audit services at the same time to their clients, has received significant public attention. One salient concern is the appropriateness of an audit division reviewing the work conducted by the tax division of the same accounting firm. During the conduct of financial statement audits, the audit engagement team undertakes detailed examinations of the validity and reasonableness of tax-related accounts in financial reports. In situations where the tax division of an audit firm has been engaged to provide tax-related services, this could impact the incentives of the accounting firms in enabling or constraining clients’ tax aggressiveness. This thesis is comprised of three related studies that provide empirical evidence of associations between accounting firms and client firms’ tax aggressiveness. Study One examines whether accounting firm office size affects corporate tax aggressiveness. Study Two explores the association between different auditor characteristics (i.e., group audit arrangements and Big 4 identity) and the tax aggressiveness of multinational enterprises (MNEs). Study Three investigates whether corporate tax aggressiveness is associated with auditors’ propensity to issue first time going-concern opinions. In addition, these three studies also explore whether factors such as whether an audit firm also provides tax services to clients, the existence of audit or tax-specific expertise, and client importance, could moderate associations between auditor characteristics and client firms’ tax aggressiveness. Study One (accounting office size study) uses a large U.S sample covering the period from 2003 to 2017 and finds that clients audited by large audit offices have lower levels of corporate tax aggressiveness. In addition, this negative relationship is less pronounced when an audit office also provides tax services or when the audit office is exposed to more complex tax issues, but it is more pronounced when a client is financially important to the audit office. Using the unique Australian listed firms’ audit fee disclosure, Study Two (group audit study) finds that MNEs are less likely to be tax aggressive when network auditors are involved in audit engagements, compared to when the principal auditor conducts the entire audit engagement, or when unaffiliated auditors are involved in the audit. In addition, Big 4 accounting firms are associated with a lower likelihood of being tax aggressive only when network auditors are involved. These results collectively suggest that the local tax and legal knowledge of network auditors, as well as their cooperation with a principal auditor’s in-house tax division, plays an important role in constraining MNEs’ aggressive tax planning. Study Three (going-concern reporting study) finds that for a large sample of U.S. financially distressed firms over the period 2003 to 2017, firms with more aggressive tax positions are less likely to receive first-time going-concern opinions. Also, this study finds that auditors are more likely to experience both Type I and Type II misclassifications when clients have aggressive tax positions, which is consistent with signalling theory. Taken together, my findings suggest that auditors obtain incremental information from tax-related accounts for going-concern decisions, but they do not succumb to pressure from tax aggressive clients. Overall, the results from this thesis provide coherent evidence supporting the argument that accounting firms have incentives to constrain their clients’ aggressive tax activities and that aggressive tax positions provide incremental information to auditors.
Going Concern, Audit Firm, Tax Aggressiveness, Group Audit
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