Is earnings management impacted by audit fees and auditor tenure? An analysis of the Big Four audit firms in the US market

Research background: Audits are intended to ensure the reliability of financial statements, as this is fundamental for different stakeholders. However, both auditor tenure and audit fees could affect the earnings management of companies. In 2014, the European Union established a mandatory audit firm rotation policy. In the United States, although there is still no mandatory regulation in this regard, there has been a large public debate over the advisability of this policy. Another unresolved controversy is whether audit fees determine audit quality. Purpose of the article: The aim of this research is to study the effect of auditor tenure and audit fees on earnings management, i.e., to determine whether a longer-term relationship between the auditor and the audited company, as well as higher audit fees, reduce the audited company's earnings management, thereby making the financial statements more reliable for stakeholders and increasing the quality of the audit report. In addition, the Big Four auditing companies in the United States were analyzed in order to determine the influence of corporate culture. Methods: A sample of companies listed in the S&P 500 stock market index was employed for the analysis, covering the years 2012 to 2021, resulting in a dataset comprising 3,010 observations. To examine the research hypotheses while mitigating the potential bias from omitted variables, a linear regression analysis was conducted using panel data with fixed effects regression. To enhance the robustness of the results, winsorized variables were also employed. Findings & value added: Overall, the results confirm that the quality of financial statements improves as auditor tenure increases, and so implementing a mandatory auditor rotation may not be in a company’s best interests. The results also support the market segmentation theory, as higher audit fees are aligned with higher quality financial reporting. Furthermore, by analyzing the Big Four audit companies in the US, it is shown that the influence of audit fees and auditor tenure on earnings management also depends on the internal aspects of the particular audit firm, especially its ethical culture. In sum, US policymakers should neither set limits on audit fees nor enforce a mandatory audit firm rotation similar to that of the EU.