The Effects of Jointly Provided Tax Services and Auditor Size on Restatements

Abstract Prior research finds evidence that audit quality is positively associated with the joint purchase of tax nonaudit services (NAS) and concludes that jointly provided tax services result in audit-related knowledge spillovers that lead to improved audit quality. We extend this line of research. We examine the relation between auditor-provided tax services and restatements and determine whether this relation differs when the auditor is a small or large accounting firm. We also examine whether the Securities Exchange Commission’s restrictions on certain tax consulting practices (SEC, 2006) altered this relation. Specifically, we measure whether the probability of financial statement restatements varies with (1) variation in accounting firm size (measured as PCAOB annually inspected firms versus PCAOB triennially inspected firms), and (2) the joint provision of audit and tax services. We find a negative relation between auditor-provided tax services and restatements which is consistent with prior research. We also find that this relation is significantly more negative when the auditor is a small accounting firm. Finally, we find that the lower probability of a restatement associated with the joint provision of audit and tax services persists regardless of auditor size after the SEC-imposed restrictions on certain tax consulting services in 2006. Our study provides evidence that accounting firms, and particularly small accounting firms, benefit from knowledge spillovers when jointly providing audit and tax services and these benefits lead to improved audit quality. Prior research concludes that large auditors provide higher audit quality and that the provision of tax services improves audit quality. Our results provide evidence that audit quality improvements are greater for small auditors and their clients. This improvement narrows that audit quality gap between large and small auditors. We do not find evidence that the SEC’s restrictions on certain tax consulting services altered the relation between audit quality and tax services.