본 연구는 개정된 「주식회사 등의 외부감사에 관한 법률」에 의하여 도입된 표준감사시간제도의 실효성에 대한 실증적 증거를 제시하고자 한다. 구체적으로 표준감사시간제도의 도입이 총 감사투입시간과 직급별 감사투입시간에 어떤 영향을 주는지 검증하였다. 나아가 표준감사시간제도 도입 이후 감사투입시간의 변화가 감사인 유형에 따라 차이가 있는지도 검증하였다. 이를 위하여 본 연구는 2018년과 2019년의 일정요건을 충족하는 2,282 기업-연도의 표본을 대상으로 분석하였다. 실증분석 결과, 첫째, 표준감사시간제도 도입 이후 감사인의 총 감사투입시간과 핵심직급(품질관리검토자, 담당이사, 등록회계사)의 감사투입시간이 증가하는 것으로 나타났다. 이러한 결과는 제도의 취지에 맞게 감사인은 감사시간을 충분히 확보하기 위해 노력하며, 나아가 감사품질 향상에도 긍정적 영향을 주는 것으로 해석된다. 둘째, 감사투입시간의 변화가 감사인 유형(Big4 여부)별로 차이가 있는지 확인한 결과 대부분의 직급에서 Big4의 감사시간 증가가 Non-Big4에 비해 더 큰 것으로 나타났지만 담당이사의 경우에는 반대인 것으로 나타났다. 이는 Non-Big4의 경우 수습공인회계사의 인력이 거의 없기 때문에 경력별가중치가 높은 담당이사의 감사투입시간을 늘려 표준감사시간을 맞추려하는 것으로 해석된다. 마지막으로 표준감사시간제도 도입으로 인한 감사투입시간의 증가는 단순감사시간 뿐만 아니라 직급별 감사시간 투입비중에도 영향을 주는 것으로 나타났다. 이러한 결과는 제도 도입 이후 감사인은 감사시간을 충분히 확보하기 위하여 노력하고 있으며, 이는 감사품질의 향상에도 영향을 주는 것으로 해석된다. 본 연구의 공헌점은 첫째, 표준감사시간제도의 실효성을 평가한 최초의 연구라는 것이며, 둘째, 총 감사시간의 변화와 함께 직급별 감사인의 감사투입시간 및 투입비중의 변화를 분석하여, 표준감사시간제도가 도입 초기에 그 취지에 따라 감사품질을 향상시키고 있는지에 대한 의미 있는 시사점을 제공하고 있다는 점이다.
This study seeks to provide empirical evidence on the effectiveness of ‘the standard audit hours policy’(the policy, hereafter) introduced under the revised Act on External Audit of stock companies. Specifically, this study analyses how the introduction of the policy affects the total audit hours and rank-specific audit hours. In addition, this study is to examine whether the change in audit hours after introducing the policy varies depending on the auditor type by size. To this end, this study analyzed 2,282 enterprise-year samples of listed companies during both 2018 and 2019. The policy was introduced in order to fundamentally improve the reliability of accounting information which has been degraded by repetitive large-scale fraudulent accounting incidents. The introduction of the policy was based on the amendment of three Acts closely related with accounting reform and advancement, which are the Act on External Audit of stock companies, the Act on the Certified Public Accountant Act, and Financial Investment Services and Capital Markets Act. The Act on External Audit of stock companies was completely amended, and the Act on the Certified Public Accountant Act and the Financial Investment Services and Capital Markets Act were partially amended. Among them, the standard audit hour system was introduced to normalize accounting audit hour and to improve audit quality. The main causes of audit failure that fails to detect accounting irregularities in a timely manner were mainly pointed out by the auditors’ low independence and insufficient audit hour. In theory, the quality of accounting audits is determined by the possibility of detecting accounting breach(i.e., errors and fraud) and the possibility of reporting the breach. The likelihood of finding accounting errors and fraud increases as the auditor’s audit effort increases, and the likelihood of reporting found accounting errors and fraud increases as the auditor’s independence increases. Accordingly, a periodic designation system was introduced to increase the independence of auditors, and a standard audit hour policy was introduced to normalize and strengthen auditors’ audit efforts. According to Article 3 of the Standard Audit Hour Regulations enacted and published by the Korean Institute of Certified Public Accountants, the definition of standard audit hour is as follows. Standard audit hour refers to the audit hour that an auditor must invest in order to faithfully comply with the accounting audit standards and maintain appropriate audit quality. Standard audit hour includes the hours related to auditing tasks(including internal accounting management system review or audit (excluding English audit), subsidiary tasks such as commissioned review, etc.) and the time spent by director, registered certified accountant, trainee certified accountant, quality control Reviewers, internal experts of the accounting firm. The results of empirical analyses are as follows. First, the total audit hours of auditors and the audit hours of key positions, which comprises quality control reviewers, partners, and registered accountants, increased after introducing the policy. These results are interpreted as auditors tried to input sufficient audit hours to meet the guideline of the newly adopted policy leading to a positive impact on the improvement of audit quality. Second, this study finds that the increase in audit hours of Big4 accounting firms is greater than Non-Big4 accounting firms for most auditor members except for audit engagement partners. This can be interpreted as an attempt of Non-Big4 accounting firms to meet the guideline of standard audit hours by increasing the audit hours of the audit engagement partner obtaining higher weight values by audit career overcoming the shortage of personnel during busy season. Finally, it is found that after introduction of the policy not only total audit hours increase but also the relative weight of rank-specfic audit hours for quality control reviewers and audit engagement partners increase. These results can be interpreted as introduction of the policy positively affects the upgrade of audit quality which is the intent of the newly-adopted policy. The contribution of this study is that first, it is the first study to examine the effectiveness of the policy; and second, it provides meaningful implications for whether the policy contributes to its intended goal, improvement of audit quality, at the beginning stage by analyzing changes in rank-specific audit hours and in relative weight of rank-specific audit hours, along with changes in total audit hours.