내부감사부서의 특성과 외부감사노력과의 관련성에 대한 연구

A Study on the Relationship between the Characteristics of the Internal Audit Department and External Audit Efforts

본 연구는 기업 내부의 감사부서가 외부감사인의 감사노력(감사시간 및 보수)에 어떻게 영향을 미치는지를 실증적으로 분석하였다. 선행연구에서는 내부감사인에 관하여 주로 감사위원회 및 상근감사에초점을 두고 내부감사와 외부감사 간 관계를 분석했다면 본 연구는 내부감사인에 관한 연구의 일환으로 내부감사부서에 대해 초점을 맞추고 있다. 한국 비금융 상장기업을 대상으로 분석한 결과, 내부감사부서를 보유하고 있는 기업은 그렇지 않은기업에 비해 외부감사 시간 및 보수가 증가하는 것으로 나타난 반면 내부감사부서의 특성이 우수할수록 외부감사인의 내부감사의존도를 증가시켜 외부감사 시간 및 보수는 오히려 감소하는 것으로 나타났다. 다만, 내부감사부서와 더불어 우수한 감사위원회가 운영되는 경우, 고품질 외부감사서비스에 대한기업의 수요가 증가하여 내부감사부서의 특성과 외부감사 시간 및 보수와의 음(-)의 관계는 다소 완화되는 것으로 나타났다. 이는 내부감사부서 및 감사위원회와 같은 기업의 내부감사기능이 외부감사인의감사수행에도 상당한 영향을 미치는 것으로 볼 수 있다.

The internal audit department plays an important role in suppressing managers' pursuit of private profits and enhancing management transparency. Since internal audits can both affect internal and external auditors, prior studies have also conducted an analysis on the relationship between internal auditors and external auditors. There are conflicting views regarding the relationship between intenral audit and external audit. Some prior studies argue that effective internal audit performance can affect external audit dependence and reduce external audit efforts. On the other hand, some argue that firms with good governance can pay attention to external audit and demand high-quality external audit to enhance reliability. Nevertheless, the above mentioned literature has some limitations such as relying on survey or experiments due to the absence of disclosure data. This study empirically analyzes how the internal audit department of a company affects the audit effort (audit time and fees) of external auditors. In the previous studies, they analyzed the relationship between internal audit and external audit by focusing on the audit committee and statutory auditors. However, this study focuses more on the role of the internal audit department by empirically analyzing how the existence and characteristics of internal audit department affects external audit efforts. We conduct an empirical analysis on firms that listed in KOSPI and KOSDAQ from 2018 and 2020. We find that companies with an internal audit department increase external audit hours and fees compared to companies without an internal audit department. However, as the characteristics of the internal audit department are excellent, the external auditor's dependence on internal audit increase and the external audit hours and fees are rather decreased. Specifically, the size of internal audit department has a negative relation between external audit efforts. Also, the larger the average number of years of service for the personnel working in the internal audit department, external audit efforts tend to be decreased. In addition, we find that the more excellent the audit committee and internal audit department are operated together, the more the company's audit demand increases, and the negative relationship between the characteristics of the internal audit department and the external audit hours and fees is weakened. It can be seen that the internal audit function of a company, such as the internal audit department and the audit committee, has a significant influence on the audit performance of external auditors. This study can be said to have the following contributions. First, compared to prior literature conducted mainly on surveys and experiments. the objectivity and reliability of the data are much better improved by using disclosure data through business reports and governance reports. Therefore, we can show that the influence on external audit efforts is different depending on the characteristics of internal audit department. In addition, we can use more detailed measures of the independence of the internal audit department to consider more diverse factors that can affect the independence of the department. In this light, we believe that this study can expand the role of internal auditors and provide policy implications for corporate governance structure including internal audit departments. Also, we think that it can contribute to rational decision-making by firms related to department operation. However, since the disclosure period for the internal audit department is short, not much data has been accumulated. Also, it is difficult to identify specific activities of the internal audit department. Despite of these limitations, we believe that our study can contribute to the existing literature regarding the internal audit department.