This study examines the conditions under which financial restatements lead corporate boards to dismiss external auditors and how the market responds to those dismissal announcements. We find that auditors are more likely to be dismissed after more severe restatements but that the severity effect is primarily attributable to the dismissal of non-Big 4 auditors rather than Big 4 auditors. We also document that among corporations with Big 4 auditors, those that are larger and more complex operationally are less likely to dismiss their auditors. Combined, this evidence suggests that firms with higher switching costs and fewer replacement auditor choices are less likely to dismiss their auditors after a restatement, which is informative to the debates about the costs and benefits of mandatory auditor rotation and limited competition in the audit market. Additionally, we examine contemporaneous executive turnover and find evidence that boards view auditor dismissals as complementary rather than substitute responses to restatements. Finally, we investigate the market reaction to auditor dismissals after restatements. The market reaction to the dismissal is significantly more positive following more severe restatements (5.9 percent) relative to less severe restatements (0.6 percent) when the client engages a comparably sized auditor. This positive market reaction is consistent with firms restoring financial reporting credibility by replacing their auditors and highlights the important role that auditors play in the financial markets. Data Availability: Data are available from public sources indicated in the text.

Research on restatements has grown significantly in recent years. Many of these studies test hypotheses about the causes and consequences of intentional managerial misreporting but rely on restatement data (such as the GAO database) that contains both irregularities (intentional misstatements) and errors (unintentional misstatements). We argue that researchers can significantly enhance the power of tests related to restatements by distinguishing between errors and irregularities, particularly in recent periods when the relative frequency of error-related restatements is increasing. Based on prior research, the reading of numerous restatement announcements, and the guidance that boards receive from lawyers, auditors, and the SEC on how to respond to suspicions of deliberate misreporting, we propose a straightforward procedure for classifying restatements as either errors or irregularities. We show that most of the restatements we classify as irregularities are followed by fraud-related class action lawsuits as compared to only one lawsuit in the group of restatements classified as errors. As further validation of our proxy, we report that the market reaction to the restatement announcement for our irregularities sample (−14 percent) is also significantly more negative than it is for our errors sample (−2 percent). Finally, we demonstrate the importance of distinguishing errors from irregularities by showing the impact it has on inferences about the relation between restatements and CEO/CFO turnover over time.