상장법인 감사인 등록제에 따른 품질관리 감사시간 증가가 감사품질에 미친 영향

According to the 'Listed Company Auditor Registration System' introduced in the 'Act on External Audit of Stock Companies' (New External Audit Act) fully revised in 2017, only accounting firms that have applied and registered with required qualifications - including human and material resources, performance evaluation and compensation and enhanced review systems - can perform audits of listed companies. As registered accounting firms would have supplemented their quality control dedicated personnel and increased quality control hours due to an increase in companies subject to preliminary review to meet requirements, this study examined the effectiveness of the new rule's implementation by analyzing the impact of increased quality control audit hours on audit quality after the introduction of the rule. In particular, since the New External Audit Act introduced various systems to improve audit quality, including the standard audit hours system, periodic designation system, and conversion of audit opinions on internal controls in addition to the auditor registration system, this study analyzed whether the introduction of the auditor registration system, measured by the increase in quality control audit hours, independently affected audit quality, separate from the effects of other systems introduced under the New External Audit Act. According to empirical analysis using performance-matched discretionary accruals as an audit quality measure for 8,245 firm-years from 2018 to 2021, the correlation between changes in quality control audit hours post-implementation compared to pre-implementation and discretionary accruals did not show significant correlation across all firm-years. However, when analyzed by asset size, improved audit quality was observed in small listed companies with assets under 100 billion won. Furthermore, this correlation was only confirmed in Big 4 accounting firms and persisted after controlling for periodic and mandatory designated audits. Therefore, it was interpreted that the introduction of the auditor registration system improved audit quality by strengthening quality control efforts for small listed companies where even Big 4 accounting firms previously had insufficient review coverage. This study makes a distinct contribution from existing research in that it independently examined the effectiveness of the auditor registration system while controlling for the mixed effects of various systems introduced by the New External Audit Act on audit quality.