본 연구는 회사가 동종 산업 내 다른 기업들과 유사한 이익창출과정을 가지고 있을 때, 감사투입시간이 줄고 감사품질이 높아지는지를 살펴본다. 개별 기업의 경영성과는 당해 산업의 경영성과와 밀접한 관련성을 가지기 때문에 감사인은 동종 산업 내 다른 기업과의 성과비교를 통해 회사의 경영성과가 비정상적인지 판단할 수 있다. 만약 회사가 동종 산업 내 다른 기업들과 유사한 이익창출과정을 가지고 있으면 감사인이 유사기업과의 비교분석을 통해 보다 손쉽게 중점감사항목을 파악할 수 있기 때문에 불필요한 정보탐색 및 입증감사에 드는 시간낭비를 막을 수 있고, 부정이나 오류를 발견할 가능성 또한 높아질 것으로 예상된다. 한편 감사인이 유사기업 정보의 활용으로부터 얻을 수 있는 이러한 효익의 크기는 감사인의 산업전문성에 따라 차별적일 수 있다. 한 편으로 아무리 좋은 정보가 주어져도 이를 해석하고 분석하는 감사인의 분석능력이 뒷받침되지 않는다면 유사기업 정보가 실질적인 유용성을 가지기 어려울 수 있다. 그러나 다른 한 편으로 산업감사경험이 다소 부족하더라도 감사인이 유사기업 정보를 잘 분석․활용하면 해당 산업에 대한 이해도를 일정 수준으로 높일 수 있기 때문에 유사기업 정보가 감사인의 부족한 산업감사경험을 보완하는 역할을 할 수도 있다. 본 연구는 2002년부터 2010년까지 기간 동안 유가증권 및 코스닥시장에 상장된 9,214개의 기업-연도를 표본으로 사용하여 이익동조성이 감사투입시간 및 감사품질에 미치는 영향을 분석하였다. 본 연구에서 이익동조성은 De Franco, Kothari and Verdi(2011)가 제시한 방법을 이용하여 측정하였다. 실증결과, 피감사회사의 이익동조성이 높을수록 감사투입시간이 줄고, 재량적 발생액이 낮아지는 것으로 나타났다. 또한 이익동조성이 감사시간을 낮추는 효과는 감사인의 산업전문성이 높을 때 보다 커지나, 이익동조성이 감사품질을 높이는 효과는 감사인의 산업전문성이 낮을 때 보다 커지는 것으로 나타났다. 본 연구는 최근 들어 감사실무에서 경영자의 의도적인 부정 적발수단으로, 그 중요성이 강조되고 있는 유사기업 정보를 감사인의 투입물(input)인 감사투입시간과 산출물(output)인 감사품질과 연결 지어 살펴보고, 그 과정에서 감사인의 산업전문성이 가지는 차별적인 효과를 검증하였다는 점에서 의의가 있다.

This study examines whether audit hours decrease and audit quality increases when a client firm has similar earnings generating process with peer firms in the same industry. As an individual firm's financial performance is closely correlated with other firms operating in the same industry, so auditors can evaluate the client firm's true performance more accurately by using the industry number. But even within narrowly defined industries, firms within the same industry frequently have different strategies, growth opportunities, and profitability, creating selection problems. One way of dealing with this issue is to focus on only those firms within the industry that have most similar earnings sensitivity for a given economic events. Earnings synchronicity captures the extent to a firm produces similar reported earnings with other firms within the same industry, for a given set of economic events. If a client firm has similar earnings generating process with firms within the same industry, the overall quantity and quality of information available to auditors about the firm is increasing. In this case, auditors can better understand their clients with relatively small efforts and more easily identify high-risk audit areas where special audit consideration may be necessary. As a result, auditors for firms with high earnings synchronicity can save time by reducing redundant information search or replacing other detailed audit testing. Also, the earnings synchronicity helps auditors judge whether there are any unusual performance changes for their clients relative to their competitors. Any unusual changes need further investigation to ensure that the reasons for the change can be fully explained, and to determine what additional tests are required to satisfy the auditor that the reported changes in performance are justified. If a client firm is more economically comparable with peer firms within the same industry, auditors can more easily detect early signs or symptoms that indicate fraud or errors. In this case, such irregularities revealed by the comparison with peer firms alert auditors that extra care and additional detailed tests are likely to be required, consequently increase the probability that auditors will detect material misstatements in the client's financial statements. Based on these reasoning, we expect that audit hours will decrease, whereas audit quality will increase in a client firm's earnings synchronicity. Meanwhile, the advantages that auditors can get from peer firms' accounting information may be different by the level of auditors' industry specialization. On the one hand, even a lot of information is available, it is of no use if it's users do not have an adequate ability to understand and interpret the audit implications contained in it. In this view, the benefits of peer firms' accounting information to the audit areas will be greater when the auditors of firms are industry specialist auditors. On the other hand, industry specialist auditors already have accumulated audit experience and deep understanding about the industry in question, so that the incremental benefits of peer firms' accounting information may be relatively low. However, non-industry specialist auditors lack industry experience or background knowledge, so that they may be highly dependent on peer firms' accounting information in order to identify the preliminary symptoms of misstatement or irregularities. In this view, the incremental benefits of peer firms' accounting information to auditors will be greater when the industry specialization of auditors is relatively low. To test these hypotheses, we use the 9,214 firm-year observations with no missing data on audit hours from the firms listed on Korea Stock Exchange and KOSDAQ for the period 2002~2010. We employ the empirical methodology of De Franco et al. (2011) to estimate firm-year level earnings synchronicity. As in other studies, we use discretionary accruals estimated by Kothari et al. (2005) as the proxy for the audit quality. Empirical results of this study show that audit hours and discretionary accruals are decreasing in earnings synchronicity. These results suggest that when a client firm is more economically comparable with other firms in the same industry, auditors can achieve audit objectives more efficiently and audit quality increases. In addition, the negative relation between earnings synchronicity and audit hours is noticeable when firms are audited by non-industry specialist auditors, whereas the negative relation between earnings synchronicity and audit hours is noticeable when firms are audited by industry specialist auditors. Overall, the results of this study suggest that earnings synchronicity affects auditors' input and output, but the effects are differential by auditor's industry specialization.

earnings synchronicity, financial statement comparability, audit hour, audit quality, industry specialist auditor