In this study, we investigate whether the increase in regulatory scrutiny epitomized by the initial PCAOB inspection impacted audit quality differentially for Big 4 and non–Big 4 auditors to better understand the consequences of PCAOB inspections for different audit firm types. Because of competing views on the effect of PCAOB inspections, the relation between PCAOB inspections and the audit quality differential between Big 4 and other auditors is an empirical issue. Empirically, we take the endogenous choice of auditor as a given and utilize a difference‐in‐differences specification that takes into account the staggered timing of the initial PCAOB inspection for different‐sized auditors in the United States. Our results suggest that the initial PCAOB inspection improved audit quality more for Big 4 auditors than for other annually inspected or triennially inspected non–Big 4 auditors. We also examine annually and triennially inspected non–Big 4 auditors separately, and find that the pre‐post Big 4/non–Big 4 differential audit quality effect is more pronounced for the triennially inspected non–Big 4 firms. In the larger context of the highly concentrated US audit market, our findings that PCAOB inspections accentuate the Big 4/non–Big 4 audit quality differential are of potential interest to public company audit clients contemplating an auditor change, investors interested in learning about the consequences of PCAOB inspections, regulators concerned about the Big 4 dominance of the US audit market, and academics investigating audit quality differences.

We examine whether peer audit choices influence a bank's decision to obtain an audit voluntarily. We find that the likelihood of a bank voluntarily obtaining an audit is significantly associated with the audit decisions of peers. The relation is stronger when the peers are more salient due to closer geographic proximity, similarity in loan portfolio, and similarity in size. In addition, we find that peer influence on a bank's audit decision is moderated by the bank's existing level of assurance. Specifically, banks already obtaining a lower level of assurance are less likely to begin an audit in response to peer influence. We also find no evidence that peer influence extends to banks' decisions to cease obtaining an audit. Overall, our findings are consistent with peer influence significantly influencing banks' decisions to begin obtaining an audit.

Recent amendments to Auditing Standard (AS) 3101 require disclosure of the initial year of the auditor‐client relationship in the audit report. As the standard was being discussed, auditors, clients, and some PCAOB members expressed reservations about the necessity of tenure disclosures and were particularly concerned about disclosing tenure in the audit report. Our purpose is to investigate whether the tenure disclosures mandated by AS 3101 are associated with changes in stakeholder behavior. We predict and find that after the implementation date, ratification votes against the auditor and the probability of subsequent auditor dismissal increase for long‐tenured versus short‐tenured auditors. Results from a path analysis further suggest that the relative increase in dismissal for long‐tenured auditors appears to be influenced directly through tenure disclosures and indirectly through ratification voting. We also predict and find that negotiating power decreases for long‐tenured auditors as evidenced by lower audit fees. Our results are comparable for companies that voluntarily disclosed and companies that did not disclose auditor tenure in their proxy statements prior to the AS 3101 amendment. Overall, our study suggests that mandatory disclosure of auditor tenure in the audit report significantly affects stakeholder behavior. The PCAOB should consider our findings carefully as they evaluate whether AS 3101 is achieving its intended purpose.