Prior research provides mixed evidence about whether competition among auditors impairs or improves audit quality. An impediment to this stream of research is the inability of researchers to observe the audit engagement bidding process. We develop a method of detecting bidding by applying a machine learning algorithm to non-incumbent (i.e., competitor) auditor views of public companies’ SEC filings. We validate our method using a proprietary sample where all instances of bidding are known. We then examine the associations between bidding, audit quality, and audit pricing. Contrary to concerns that competitive pressure may cause auditors to compromise their independence, we find that incumbent auditors perform higher quality audits during bidding years. This improvement in audit quality occurs regardless of whether the bidding ultimately results in an auditor change and persists for several years when the incumbent auditor wins reappointment. We also find that bidding is associated with modest audit fee concessions.

We investigate whether non‐GAAP reporting affects the audit process and thereby the quality of the related financial statements. First, we provide evidence that auditors in numerous countries, including the United States and the United Kingdom, rely to varying degrees on non‐GAAP profit before tax as a benchmark for determining quantitative materiality. Then, using Premium Listed companies on the London Stock Exchange, we document that U.K. auditor reliance on non‐GAAP materiality benchmarks often results in a higher quantitative materiality amount and can lower audit quality. Although U.K. auditors appear skeptical of managers’ more aggressive non‐GAAP adjustments, auditors adopt more of management's low‐quality adjustments when auditor independence is weaker. In sum, our results suggest that non‐GAAP reporting can indirectly affect investors by reducing the rigor of the financial statement audit.