Regulators and others recently highlighted the increasingly important
role of internal auditing in supporting and interacting with the
audit committee to ensure the integrity and quality of financial
reporting. Likewise, one of the roles of the audit committee is to
oversee the quality of monitoring mechanisms implemented by
the firm, which includes the internal audit function. However,
our understanding of the relationship between the audit committee
and internal auditing is limited. We fill this void by providing
the first empirical evidence of the association between audit committee
characteristics and the investment in internal auditing. Our
analyses, from a sample of 181 SEC registrants, suggest that the
investment in internal auditing (internal audit budget) is negatively
related to the presence of auditing experts on the committee
and the average tenure of audit committee members, but positively
related to the number of audit committee meetings (a proxy
for audit committee diligence). These observations suggest potential
complementary and substitution effects between the audit
committee and internal auditing, and thus raise important implications
for future research.