Why are expanded audit reports not informative to investors? Evidence from the United Kingdom

Standard-setters worldwide have passed new audit reporting requirements aimed at making audit reports more informative to investors. In the UK, the new standard expands the audit reporting model by requiring auditors to disclose the risks of material misstatement (RMMs) that had the greatest effect on the financial statement audit. Using short window tests, prior research indicates that these disclosures are not incrementally informative to investors (Gutierrez et al. in Review of Accounting Studies 23:1543-1587, 2018). In this study, we investigate three potential explanations for why investors do not find the additional auditor risk disclosures to be informative. First, using long-window tests, we find no evidence that the insignificant short-window market reactions are due to a delayed investor reaction to RMMs. Second, using value relevance tests, we show that the insignificant market reactions are not due to auditors disclosing irrelevant information. Finally, we provide evidence suggesting that RMMs lack information content because investors were already informed about the financial reporting risks before auditors began disclosing them in expanded audit reports.