In recent years, public accounting firms have experienced a steady increase in the proportion of their revenues generated from consulting services. Although growth in consulting revenue following the Sarbanes‐Oxley Act (SOX) has been generated primarily from services provided to nonaudit clients, regulators have expressed concerns about the potential implications of this increase for audit quality. In contrast, accounting firms assert that the expertise developed by their consulting professionals helps them to provide better quality audits. We examine the relation between the proportion of accounting firm consulting revenue to total revenue and audit quality and investor perceptions of audit quality. Because SOX drastically altered the source of consulting revenues for public accounting firms, we also separately examine these relations in the pre‐ and post‐SOX eras. We find evidence suggesting that before SOX, higher proportions of audit firm consulting revenues negatively impacted both audit quality and investor perceptions of audit quality. However, we do not find a statistically significant association between audit firm consulting revenues and either audit quality or investor perceptions of audit quality following SOX. Our analyses suggest that even if these relations exist following SOX, the potential economic magnitude of the effect is small.

In this study, we examine whether audit committee accounting expertise helps to promote audit quality by motivating auditors to conduct diligent internal control audits and make appropriate internal control assessments because audit committee accounting expertise safeguards auditors from dismissal following adverse internal control opinions. Among clients with existing and likely internal control material weaknesses (as proxied by future restatements of audited financial statements), we find a greater likelihood of adverse internal control audit opinions when the audit committee has greater accounting expertise (measured by the proportion of accounting experts on the audit committee). Among all clients, we find a lower likelihood of subsequent auditor dismissal following an adverse internal control audit opinion when the audit committee has greater accounting expertise. In further analyses, we find that this lower likelihood of subsequent auditor dismissal occurs when at least two audit committee members possess accounting expertise. We also find some evidence that CFO influence (but not CEO influence) over the audit committee negates the increased likelihood of adverse internal control opinions when internal control material weaknesses likely exist, as well as the decreased likelihood of auditor dismissal following adverse internal control opinions. These findings have important implications for regulators and corporate nominating committees interested in promoting audit committee effectiveness.