주기적 감사인 지정제와 표준감사시간 제도는 공존할 수 있는가?: 2020년 감사인 지정 여부를 활용한 발생액의 질에 대한 준실험적 연구

This study investigates how the coexistence of two regulatory mechanisms—periodic auditor designation rule and standard audit rule—affects audit quality in Korea. Following the implementation of the New External Audit Act, regulators have introduced multiple audit-related mandates aimed at enhancing audit quality, whereas critics have raised concerns about excessive regulatory costs and potential audit inefficiencies. To empirically assess the effectiveness of these overlapping regulations, this study evaluates whether the two regulatory rules contribute efficiently to audit quality. Using innate accrual quality and discretionary accrual quality as proxies for audit quality, as proposed by Francis et al.(2005), and adopting a quasi-experimental design via the difference-in-differences method, this study analyzes the total sample of 851 from 2019 to 2021. The treatment group is identified based on a decision-tree classification algorithm that infers periodic designated auditor. The empirical results are threefold. First, firms audited by periodic designated auditors exhibit significantly improved innate accrual quality, whereas the effect on discretionary accrual quality is not statistically significant. Second, periodic designated auditors tend to reduce the deviation between actual-standard audit hours. Third, the positive association between actual-standard audit hours and innate accrual quality is more pronounced for periodic designated auditors, indicating greater audit efficiency. Overall, these findings suggest that despite concerns about regulatory redundancy, the joint operation of the periodic auditor designation rule and standard audit hours rule contributes to enhancing audit quality without inducing audit inefficiency. This evidence provides support for the theoretical premise that these audit reforms can function complementarily to improve audit outcomes in practice.