비정상감사시간과 비정상심리시간이 자기자본비용에 미치는 영향과 감사인 규모의 조절효과

[Purpose] This study examines the effects of abnormal audit hours and abnormal internal audit quality assurance hours on the cost of equity capital and the moderating effect of audit firm size. [Methodology] Using the relevant financial statements data and samples of 709 firmyears listed in Korea Exchange between 2014 and 2016, this study conducts regression tests on the effects of abnormal audit hours and abnormal internal audit quality assurance hours on the cost of equity capital and the moderating effect of audit firm size. [Findings] The general association between abnormal audit hours and the cost of equity capital is partially supported by empirical evidences. More specially, it is supported that as abnormal internal quality assurance hours are higher, the cost of equity capital measured by Easton(2004)’s PEG decreases. But in a sample of positive abnormal audit hours, as abnormal audit hours are higher, the cost of equity capital increases rather than decreases. And it shows that there was no evidence of the moderating effect of audit firm size on relationship between abnormal audit hours or abnormal internal quality assurance hours and the cost of equity capital in a full sample. But audit firm size moderates relationship between abnormal audit hours and the cost of equity capital in a sample of positive abnormal audit hour. [Policy Implications] As follows are the meanings of these findings. First, internal quality assurance is internal control system of audit firm in order to improve its audit quality. So, higher internal quality assurance hours results in increasing the reliability of accounting information and decreasing asymmetry of information and information risk that finally leads to lower the cost of equity capital. Second, audit quality of Big4 may not be higher than that of non－Big4. This result is different from previous studies. This means that both Big4 and non－Big4 need to make additional efforts to improve and differentiate their audit quality.