내부회계관리제도의 효과성 검증 - 타인자본비용을 중심으로

The accounting scandal in the U.S. in early 2000's leads to the enactment of SOX(Sarbanes-Oxley) which emphasized the importance of internal control system in section 404. SOX affected accounting system in Korea and led to pass the new accounting legislation in April 2004. One of the acts in new accounting legislation is the internal control over financial reporting system(ICOFR) which is similar to Section 404 of SOX. In ICOFR, manager should evaluate the internal control system of company, issue a evaluation report of internal control system and get a authentication by CEO or CFO. Auditor also should issue a opinion about company's internal control system as well as evaluate the manager's evaluation report of internal control system. Auditor should issue a report about company's internal control system attached to a annual audit report. Therefore, we could think that internal control system was strengthened after the enactment of ICOFR. There were many studies which found the effectiveness of ICOFR. But their results were controversial : Sohn and Chung(2009) and Cho and You(2006) found that ICOFR was effective but Ahn and Choi(2008) and Choi and Moon(2009) found that it was not. In this study, we used the cost of debt capital(interest expense / non current debt) which is used as a proxy of information asymmetry. If the ICOFR was effective, the reliability of financial statement would be enhanced and the company could reduce the cost of debt capital. Investors would demand lower interest rate because they could reduce risk premium such as risk of bankruptcy. In empirical results, cost of debt capital of company which adopted ICOFR was significantly lower than that of company which did not adopt. And the cost of debt capital of year after the ICOFR reduced significantly compared to year before ICOFR. This is because reliability of company which adopted ICOFR increased due to the strengthened control of internal control and managers could reduce the information asymmetry between managers and investors. And, the company which received a qualified opinion(material weakness and scope limitation) had a higher cost of debt capital than company which received a unqualified opinion. Investors were not confident of reliability of company which got a qualified opinion because of the risk such as bankruptcy and credit. Therefore, they required more risk premium. In summary, we found that cost of debt capital reduced significantly after the ICOFR and company which adopted the ICOFR was significantly lower than that of company which did not adopt the ICOFR. Also, investors demanded a higher risk premium of company which received a qualified opinion. Therefore, we conclude that the ICOFR is effective.