상장회사 감사인등록제 시행이 비상장회사에 대한 감사품질에 미치는 영향

The 2016 Daewoo Shipbuilding & Marine Engineering accounting fraud case served as a catalyst for comprehensive revisions to the Act on External Audit of Stock Companies as part of Korea’s accounting reform. The New External Audit Act included a number of systems that had been continuously discussed to improve accounting transparency in the past, and the registration system for auditors of listed companies allowed external audits of listed companies only to accounting firms that met certain registration requirements, which brought a major change in the external audit market environments. This system aimed to improve audit quality by promoting the growth and organization of accounting firms. However, despite these intentions, the quality management of accounting firms did not meet market expectations. The strict registration requirements have limited competition, leading to sharp increases in audit fees, and recent violations of regulations by registered auditors have raised questions about the system’s effectiveness. This study examines changes in audit quality for non-listed firms following the implementation of the auditor registration system. While previous research has focused exclusively on listed firms, it is important to analyze the impact of changes in the external audit market on the audit quality of non-listed firms, which constitute the majority of companies subject to external audits. Our empirical analyses show that audit quality for non-listed companies audited by registered auditors improved after the implementation of the auditor registration system. However, no significant difference was found in the extent of audit quality improvement between BIG4 and NON-BIG4 accounting firms. Interestingly, the audit quality of non-listed companies audited by non-registered auditors also enhanced, which suggests that this improvement was more likely driven by changes in the external audit market than by the auditors’ own capabilities, as non-registered auditors are not directly affected by registration requirements. Although the concurrent implementation of multiple new systems, along with the COVID-19 pandemic, makes it difficult to isolate the pure effects of the auditor registration system, this study extends prior research by being the first to analyze the effect of auditor registration system on the audit quality of non-listed firms, an area that has received relatively little attention. Our findings offer important policy implications for regulatory authorities in the future operation of the auditor registration system.