A key premise underlying the case for mandatory rotation is the proposition that long auditor tenure fosters “coziness” between the audit firm and company management that dulls the audit team’s independence, objectivity, and professional skepticism.
The hypothesis is that audit quality problems are correlated with extended auditor tenure. However, our review of the literature found evidence that, if audit quality problems do occur, they are less likely later in the auditor’s term. This is consistent with the observation that a deep understanding of the specific business being audited takes time to accumulate.
A 2004 study by professors Joseph Carcello and Albert Nagy is indicative of the findings in the literature. They examined the relationship between audit firm tenure and financial reporting fraud, and found that fraud is more likely to occur in the first three years of the auditor-client relationship.14
Other academic research similarly finds that risks to audit quality occur more frequently during the first or second year of an engagement.15 Examination of financial reporting data supports these conclusions. Studies of fraud at public companies tend to show a correlation to changes in auditors.16 Research indicates the likelihood of a restatement diminishes as auditor tenure increases.17
Additionally, a recent analysis of the Russell 1,000 companies performed by Audit Analytics revealed no instances in which a new auditor discovered problems within one year of the auditor change and initiated an annual restatement of financial statements audited by the prior auditor.18
Our own experience bears out the research findings and conclusions. PCAOB inspections of Deloitte audits tend to show a higher rate of adverse Part I findings during the first 10 years of an audit engagement, compared to rates for engagements where tenure is greater than 10 years.
The Concept Release raises the question of whether correlations that relate to voluntary, rather than mandatory, changes in auditors are pertinent. There is evidence that the same pattern holds true in countries that have implemented mandatory audit firm rotation, Italy being an example