On the Measurement of Auditing Standards

This study analyzes whether it is appropriate to use the percentage of qualified opinions issued by an auditor as a measure of his auditing standards, as is often done. It points out that incentives exist for auditors to specialize by auditing standards, and for clients to self‐select on this dimension. As a result, even if auditing standards affect the propensity to issue qualified opinions, the observed percentages of qualified opinions will not necessarily reflect differences in auditing standards. This proposition is supported empirically with US data. A sample of auditors was split between a “higher standard” and a “lower standard” category based on the percentage of qualified opinions issued. After controlling for client firm size, leverage, systematic risk and “unexpected” earnings, auditing standard category is found to have no significant relation with firm‐specific stock returns.