본 연구는 (ⅰ) 한국 회계감사 시장에서 고유정보위험요인(본질적 정보위험과 재량적 정보위험)이 감사보수에 충분히 반영되고 있는지를 조사하고, (ⅱ) 고유정보위험요인에 따라 감사의견구매와 감사보수할인 행태가 차별적으로 결정될 수 있는지를 분석한다. 이를 통해 위험과 가격이 비례하지 않는 감사보수 가격결정체계의 비효율성이 감사의견구매(감사보수 할인)행태에 영향을 미치는 부분적인 상황 요인이 될 수 있는지를 실증적으로 조사하는 것에 초점을 맞추고 있다. 분석 결과를 요약하면 다음과 같다. 첫째, Francis et al.(2004, 2005)에 따라 개별기업의 기본적 정보위험과 재량적 정보위험을 회계 수치를 이용하여 측정하고, 각 위험 요소가 감사보수에 유의하게 반영되고 있는지를 분석하였다. 그 결과 기본적 정보위험은 감사보수와 유의한 양(+)의 관계를 보였지만, 재량적 정보위험은 감사보수와 유의한 관계를 보이지 않았다. 이러한 결과는 대리인 위험에 기인한 정보위험(재량적 정보위험)이 감사보수에 충분히 반영되지 않고 있음을 의미하며, 이는 감사보수 가격결정체계에 부분적인 비효율성이 존재할 가능성을 시사한다. 둘째, 감사의견구매 및 감사보수할인 행태가 고유정보위험이 큰 표본에서 더 크게 발생하는지를 분석하였다. 분석결과, 양(+)의 비정상감사보수를 지급하는 표본에서 비정상감사보수와 이익조정 간에 양(+)의 관계가 관측되는 현상(감사의견구매)과 음(-)의 비정상감사보수를 지급하는 기업에서 비정상감사보수와 이익조정 간에 음(-)의 관계가 관측되는 현상(감사보수할인)은 모두 재량적 정보위험이 큰 표본집단에서 그 강도가 증가한다는 것을 확인하였다. 이러한 결과는 재량적 정보위험이 감사보수에 충분하게 반영되지 않은 기업은 감사의견구매와 감사보수할인 행태가 더 크게 발생할 수 있음을 시사한다. 전반적으로 본 연구의 결과는 고유정보위험요인(특히 재량적 위험)이 가격에 불완전하게 반영되는 경우 비정상감사보수를 이용한 지대추구행위가 더 증가할 가능성이 있음을 실증적으로 보여주고 있다.
This study is to investigate whether the audit fee is efficiently determined in Korean market and if not, inefficient audit pricing system can aggravate the opportunistic behavior of audit opinion shopping and audit fee discount. If the negotiation power between auditor and client is not balanced, audit fee will deviate from the optimal price, in turn aggravating opportunistic motives of auditors and management. Prior capital markets studies assert that firm-specific information risk may not be fully diversified, and such undiversified risk can be a determinant of stock price by influencing the expected rate of return of investors. Supporting this argument, there are empirical evidences that the investors take undiversified risk (i.e., unsystematic risk) into account when they access the pricing of the firm value. In other words, as firms with higher firm-specific information risk entail higher adverse selection risk to investors, investors demand additional rewards for risky investment, resulting in higher cost of capital in firms with high information risk. This study assumes if the audit fee is efficiently determined as stock prices in the capital markets, we would observe audit fee is correspondingly increases as audit risk (i.e., firm-specific information risk) increases. Under this assumption, we analyze whether audit fee systematically reflects firm-specific information risk factors (innate and discretionary information risk, respectively). Then, we try to show whether it can be a situation that facilitates the behavior of audit opinion shopping and audit fee discount when the audit fee is not efficiently priced according to firm specific information risk. That is, if the audit fee pricing system is efficient, it adequately reflects the firm-specific information risk, and as a result, opportunistic acts such as audit opinion shopping or audit fee discount will be suppressed. However, if the audit market is inefficient in terms of audit fee agreement, the firm-specific information risk will not be efficiently reflected in the audit fee, resulting in underpriced audit fee. As a result, it makes for firms that particularly have high information risk to easily engage in shopping around audit opinions and discounting audit fees. Based on this reasoning, this study tries to analyze whether the Korean audit market is efficient in terms of audit fee agreement by analyzing the relationship between firm-specific information risk and audit fee. Using the Korean firms listed in KOSPI between 2004 and 2016, the empirical results are as follows. First, we measured firms' intrinsic and discretionary information risks according to Francis et al. (2004, 2005), and analyzed whether each risk factor has systematic relationship with audit fee. The evidence shows that innate information risk (i.e., innate accruals quality) has a significantly positive relationship with audit fee whereas discretionary information risk (i.e., discretionary accruals quality) does not. This result implies that the information risk potentially arising from agency problem may not be efficiently reflected in the audit fee at least partially. Second, we analyze whether opportunistic behaviors (namely, audit opinion shopping and audit fee discount) occur more in the firms with higher firm-specific information risk. The evidence in the sample of positive abnormal audit fee shows that there is a positive relationship between abnormal audit fee and earnings management, suggesting managers' audit opinion shopping by paying higher abnormal audit fee. Further, the positive relationship is more pronounced in firms with higher discretionary information risk. In addition, in the sample of negative abnormal audit fee, we find that the negative relationship between the abnormal audit fee and earnings management and the relationship is stronger in firms with higher discretionary information risk, suggesting audit fee discounting with lower audit efforts. In contrast, innate information risk does not affect the relationship between abnormal audit fees and earnings management. These results suggest that when discretionary information risk is not adequately priced in audit fees, audit opinion shopping and audit fee discount behavior may occur more in firms having severe agency problems. The findings of this study provide the following implications. First, our results present the specific circumstances (such as firm-specific information risk in this study) that supports the existing literature, arguing there is a certain situation which facilitates audit opinion shopping and audit fee discount behavior. Second, this study provides additional evidence that the accruals quality is useful to measure auditor's residual risk. Finally, regulatory agencies are moving forward to strengthen the regulations by amending the External Audit Act (including periodic auditor designation, standard audit hours policy, and auditing internal accounting control system) to alleviate information asymmetry and market imperfection. The results of this study support the current policy direction of regulatory agencies.