내부감사부서가 감사보수 및 감사노력에 미치는 영향: 감사인 교체를 중심으로

The Internal Audit Department is an organizational unit responsible for supporting audit committee activities and conducting internal audits. This study examines whether the presence of an internal audit department in client firms, along with its characteristics (size, independence, and competence), affects audit fees, audit efforts, and audit quality following auditor switches. Consistent with prior studies, we find that auditor switches lead to increases in audit fees and hours. However, this effect is mitigated when the client firm has an internal audit department, particularly when the department is larger and more independent. In addition, the hourly audit fee decreases when the internal audit department is more independent. Importantly, the presence and characteristics of the internal audit department have no significant effects on audit quality around auditor switches. We further confirm the robustness of our results by incorporating additional controls related to financial reporting quality, information environment, and governance. Moreover, we find consistent results using propensity score matched samples, entropy-balanced samples, and Heckman’s (1979) two-stage regression model. In summary, this study presents empirical evidence supporting the role of the internal audit function during auditor switches and provides important implications for regulators, academics, and practitioners.