공정공시와 관련된 내부자거래의 동기에 관한 연구

이정엽(Jung Youp Lee),김문철(Moon Chul Kim),전영순(Young Soon Cheon) 한국증권학회 2013 한국증권학회지 Vol.42 No.2

기업 내부자는 외부자와의 정보비대칭을 해소하기 위해 공시와 내부자 보유지분율이라는 두 개의 신호를 활용할 유인이 있다. 본 연구에서는 공정공시 후에 이루어지는 내부자거래가 사적이익을 얻기 위한 동기(사적이익동기가설) 외에 공정공시된 정보에 대한 추가적인 신호를 전달하기 위한 동기(내부정보신호가설)인지를 분석한다. 실증분석 결과, 좋은 소식(good news)의 공정공시 후에 매도거래가 증가하며, good news 공정공시로 인한 주가상승폭이 클수록 매도거래의 크기는 증가 하는 것으로 나타난다. 또한, 내부자는 나쁜 소식(bad news)의 공정공시로 인한 주가하락폭이 클수록 매수거래를 수행하는 경향이 있다. 이러한 결과는 공정공시 후의 내부자거래가 사적이익동기에 따라 이루어지고 있음을 의미한다. 이와 같은 사적이익 동기는 최고경영자 그룹에서 심화된다. 또한, 내부자거래가 공정공시된 정보에 대해 추가적인 신호를 전달하기 위한 동기에서 수행된다면 공정 공시되는 정보가 미래지향적이고 서술적일수록 내부자거래가 증가될 것으로 예상된다. 그러나 공정 공시 후의 내부자거래는 공정공시되는 정보의 속성 및 유형과 유의한 관련이 없는 것으로 나타 나는데, 이는 공정공시 후에 이루어지는 내부자거래가 공정공시되는 정보에 대한 추가적인 신호 기능을 위해 수행되는 것은 아님을 의미한다. This paper investigates two competing hypotheses as an explanation for the motives for insider trading following Fair Disclosures (FD)-personal profit hypothesis and signaling hypothesis. The results reveal that insiders tend to sell their company stocks after good news FD and buy their company stocks after bad news FD. Post-FD insider selling is positively associated with market reactions to FD, and post-FD insider buying is negatively related to the market reactions to FD. Also, the magnitude of post-FD insider selling increases alongside the magnitude of the positive market reactions to FD. The positive relationship between post-FD insider selling (buying) and positive (negative) market reactions to FD is more salient for insiders who are the top management of the firm. We also find that post-FD insider trading is not affected by the type of FD. Neither qualitative FD nor forward-looking FD alters patterns of post-FD insider trading.

시차와 전력 분석을 이용한 새로운 스마트카드 트랩도어 검출방법

이정엽(Jung Youp Lee),전은아(Eun-A Jun),정석원(Seok Won Jung) 한국정보보호학회 2005 정보보호학회논문지 Vol.15 No.5

현재의 스마트카드는, 경제적인 이유 때문에 보안 문제가 발생할 수 있음에도 불구하고, 카드를 재사용할 수 있는 초기화 명령어와 패치 코드를 추가할 수 있는 패치 명령어가 들어있는 경우가 많다. 이러한 트랩도어 명령어들은 세련된 기법으로 만들어지고 일반에게 공개되지 않기 때문에 기존의 테스트 소프트웨어로 검출하는 것은 매우 어렵다. 지금까지 알려진 가장 효율적인 방법은 ITSEC에서와 같이 개발과정을 통제하고 소스 코드를 분석하는 것이다. 그러나 이러한 방법은 오랜 시간을 요구하고 비용이 많이 든다. 이에 본 논문에서는 시차 분석과 전력 분석을 이용하여 스마트카드의 트랩도어를 검출할 수 있는 새로운 방법을 제안한다. 그리고 실험에 의해 제안한 방법이 효율적이며 실질적인 접근 방법임을 보여준다. For economic reasons, even though there are some security problems, the commands of re-initializing and writing patch code are widely used in smart cards. The current software tester has difficulty in detecting these trapdoor commands because trapdoors are not published and programmed sophisticatedly. Up to now the effective way to detect them is to completely reveal and analyze the entire code of the COS with applications such as the ITSEC. It is, however, a very time-consuming and expensive processes. We propose the new detecting approach of trapdoors in smart cards using timing and power analysis. With our experiments, this paper shows that the proposed approach is more practical than the current methods.

연구논문 : 외국인투자자의 투자성과와 보수주의 및 국제회계기준

김영(제1저자) ( Young Kim ),이정엽(교신저자) ( Jung Youp Lee ) 한국회계학회 2015 회계저널 Vol.24 No.3

본 연구는 외국인투자자가 우월한 정보분석 및 해석능력으로 내국인투자자보다 우수한 투자성과를 이루었는지 분석하고, 외국인투자자의 투자성과에 영향을 미칠 것으로 예상되는 보수주의 및 국제회계기준 도입과의 관련성을 분석한다. 외국인투자자의 투자성과 측정을 위해서 투자자의 성과측정치로서 적합한 Dichev(2007)의 내부수익률(IRR)을 적용한다. 2002년부터 2012년까지 외국인이 투자한 기업을 대상으로 총 3,394기업-년도의 표본에 대하여 분석을 수행하였으며, 주요 실증분석 결과는 다음과 같다. 첫째, 분석기간 동안 외국인투자자는 내국인투자자보다 우수한 투자성과를 보인 것으로 나타났다. 이는 외국인투자자의 정보분석능력과 해석능력이 내국인투자자보다 우월함을 의미한다. 둘째, 보수적인 회계처리를 수행한 기업일수록 외국인투자자의 투자성과와 내국인투자자의 투자성과 차이는 심화되는 것으로 나타났다. 이러한 결과는 외국인투자자가 보수적인 회계처리를 수행하는 기업들에서 내국인 투자자들보다 우수한 수익률을 얻었음을 의미하는 것으로서, 외국인투자자가 투자의사결정과정에서 내국인투자자들에 비해 기업의 보수주의 정보를 보다 효과적으로 이용하고 있음을 시사한다. 셋째, 국제회계기준의 도입 이후에 외국인투자자의 투자성과와 내국인투자자의 투자성과 차이는 심화되는 것으로 나타났다. 이는 국제회계기준의 도입으로 인하여 국가간 회계정보의 비교가능성이 증대되어 외국인투자자가 보다 수월하게 해당 기업의 회계정보를 분석하고 해석할 수 있게 되었음을 의미한다. 본 연구는 투자자의 현금흐름을 추정하여 내부수익률(IRR)을 이용한 투자성과를 적용하고, 외국인투자자의 투자성과와 보수주의 및 국제회계기준 도입과의 관련성을 분석하였다는 점에서 선행연구와 차별화된다. The size of foreign investment has been increasing and in the financial study field, whether foreign investors can have a better performance than domestic investors has been main issue. In general, foreign investors`` performance can be superior to domestic``s. But this thought could not remain for such a long time, because of sample period, market category, and research methodology. So we cannot for sure that performance of foreign investors are better than domestic investors. Many prior literatures said that foreign investors have specialized international experiences in investment, a good ability for analysis and interpretation for firm and market informations. They can use this ability for invest decision making, so that they can have a better profit rate than here in Korea. But other studies said that foreign investors have a difficulty in getting informations of firm and market. So their investment profit is not as good as we thought. In Korea security market, foreigners`` investment was active after 1998 financial crisis, many prior study has been processed using before IMF crisis data. Considering the prior research (foreign investor``s performances are better than other``s after IMF crisis), there is possibility of different results if we use current market data. In addition, many prior studies used buy-and-hold return for calculating profit rate. This measure is proper for individual firm``s performance, but not for invertor (Dichev and Yu 2011). So we measure foreigners`` performance using internal rate of return (IRR). Basically by using share price and number of share, we estimate foreign investors`` and domestic investors`` cash flow. After that, we estimate each investors`` IRR. We expect that foreign investors are more prefer conservative accounting than others. So they have more interesting in conservative firm. In short-term perspective, conservative accounting is negative to firm``s profit, but has positive effect to firm``s value in the long-term perspective. If foreign investors consider short-term and long-term effect, then using thisconservative information data in investing process, they get more. We also expect adoption of IFRS has effect on this process. IFRS accounting information has many advantages in comparison information in different countries and foreigners are more accustomed to IFRS. That has more positive effect on foreigners`` profit. This paper examines whether foreign investors earn higher return than domestic investors`` due to the differences of information analysis ability. In addition to this topic, we also analyze the impacts of conservatism and adoption of IFRS to the foreign investors performance. We use Dichev(2007)``s IRR(Internal rate of return) to measure investor``s performance, and measure conservatism using Khan and Watts(2009) and Paek and Lee(2004)``s methodology. Our sample consists of 3,394 firm-years from 2002 to 2012. The findings of this study are as follows. First, foreign investors`` IRR is higher than that of domestic investor on our test periods. It implies that foreign investors may have ability to sophisticated investment skills. Second, the degree of conservatism makes differences of investment return between foreigners and domestic investors. In other words, the foreign investor had higher returns on the more conservative firms. This result shows that foreign investors use the information of firms``s conservatism more effectively on the investment decision making process than do domestic investors. Third, adoption of IFRS makes bigger differences of investment return between foreigners and domestic investors. We interpret that IFRS plays an important role in decreasing information asymmetry between foreign and domestic investors. We contribute to previous accounting literatures by using new measure of investment performance between foreign and domestic investors, conservatism and adoption of IFRS.

회계법인의 재무적 특성이 감사품질에 미치는 영향

황문호 ( Mun Ho Hwang ),이정엽 ( Jung Youp Lee ),안성희 ( Sunghee Ahn ) 한국회계학회 2015 회계저널 Vol.24 No.4

감사품질이 외부감사인의 적격성과 독립성에 의해 결정될 수 있음을 전제하면, 회계법인의 재무적 특성은 이들 적격성과 독립성에 직 간접적인 영향을 미침으로써 결과적으로 감사품질과도 유의한 영향관계를 맺을 것으로 예상된다. 본 연구는 회계법인의 사업보고서로부터 감사품질과 관련성이 높을 것으로 예상되는 재무적 특성변수를 선별한 후, 이들 특성과 감사품질의 관계를 실증적으로 분석하였다. 구체적으로 본 연구는 회계법인의 생산성, 수익성, 재무건전성, 감사매출비중 등이 감사품질에 미치는 영향을 분석하였다. 본 연구는 국내 121개 회계법인이 2004년부터 2010년까지 수행한 7,203기업-연도의 외부감사업무를 대상으로 분석하였으며, 감사품질의 대용치는 피감사기업의 이익 속성을 나타내는 재량적 발생액과 회계오류 여부를 사용하였다. 실증분석 결과, 재무건전성이 낮은 회계법인일수록 감사품질이 낮은 것으로 나타났으며, 매출액에서 감사업무가 차지하는 비중이 높을수록 전반적인 감사품질이 높은 것으로 나타났다. 또한 등록회계사 1인당 매출액이 많을수록 회계사의 업무부담이 가중되어 피감사기업의 재무제표에 오류가 포함될 가능성이 높은 것으로 나타났다. 감사품질을 결정하는 주요 주체는 외부감사인이라는 점에서 회계법인의 특성과 감사품질의 관계를 밝히는 것은 감사연구에서 매우 중요한 분야이다. 본 연구는 회계법인의 규모나 산업전문성 등에 초점을 맞춰왔던 선행연구를 확장하여 회계법인의 재무적 특성과 감사품질의 관계를 분석하였다는 점에서 차별성이 있다. 아울러 감사품질의 제고를 위해서는 회계법인의 재무상태나 수익구조가 모니터링 될 필요성이 있음을 제기하는 본 연구결과는 회계감독기관이나 자본시장의 이해관계자들에게 유용한 시사점을 제공하는 것으로 판단된다. This paper examines the relation between auditor``s financial characteristics and audit quality. Given that audit quality is jointly determined by auditor competence and independence, auditor's financial characteristics, such as productivity, profitability, financial soundness, and relative importance of audit service, may have an impact on audit quality by directly/indirectly affecting auditor competence and independence. To test the association between auditor``s financial characteristics and audit quality, this paper uses performance matched discretionary accruals(PMDA), and accounting errors(ERROR) as proxies for audit quality. Also we consider productivity, profitability, financial soundness, and relative importance of audit service as a auditor``s financial characteristics. We predict that the higher productivity is, the lower audit quality is.(hypothesis 1) This is based on Choe(2012) reporting that immoderate works of individual CPA cause of low-audit quality. We use the revenue per a CPA as a proxy for productivity. Also, we anticipate that the worse auditor``s profitability and financial soundness are, the lower audit quality is.(hypothesis 2 and 3) Because auditors with poor profitability and financial soundness can tend to discount audit fee for accepting business, this may lead to spend less audit hours than required hours and affect negatively to audit quality. Also they may be exposed to opinion shopping more easily than auditors with good financial soundness. Lastly, we consider the relative importance of audit service. The higher the relative weight of revenue from audit service in audit firm is, the more audit firm may be concerned in audit service in order to prevent the loss of reputation from audit failures.(hypothesis 4) This paper investigates audit quality data of 7,203 firms-years from 2004 to 2010, and the results are as follows. First, the likelihood that errors are included in client firms`` financial statements decreases as auditor's productivity decrease. This means that the immoderate works of individual CPA can induce some mistakes and affect to audit quality negatively. Second, it is observed that the weaker financial soundness of audit firms are, the lower the audit quality is. This implies that auditors with poor financial soundness provide the poor auditing service, because they tend to excessively discount the audit fees and accept business with the purpose of recovering the financial status. Third, audit quality is positively related with relative importance of auditing in auditor``s total revenue. Audit firms with high revenue from audit service are specialized in auditing, so the potential loss from audit failures can be large to them. This result implies that auditors relatively specialized in audit service are more careful of audit quality. Investigating the relation between auditor characteristics and audit quality can be viewed as one of the primary subjects in audit research. Extending the prior studies which mainly focus on the size or the industry expertise as auditor``s characteristics. Our contribution is that we incorporates various financial characteristics of auditors, which are productivity, profitability, financial soundness, and relative importance of audit service. Especially, we find that auditor``s financial soundness and the importance of audit service affect to audit quality. The results that audit firms`` various characteristics should be taken into account for the improvement of audit quality have implications for the supervisory authority for audit firms and market participants.

고엽제 노출과 병원 밖 심정지 후 생존 퇴원과의 연관성

김동욱 ( Dong Wook Kim ),계유찬 ( Yu Chan Kye ),이정엽 ( Jung Youp Lee ),정의기 ( Eui Gi Jung ),김동성 ( Dong Sung Kim ),최현정 ( Hyun Jung Choi ),이영 ( Young Lee ) 대한임상독성학회 2021 대한임상독성학회지 Vol.19 No.1

Purpose: We investigated the association between defoliant exposure and survival to discharge after out-of-hospital cardiac arrest. Methods: This is a retrospective case-control study based on the cardiopulmonary resuscitation (CPR) registry. The electronic medical records of out-of-hospital cardiac arrest victims from 6/9/2008 to 12/31/2016 were analyzed statistically. The case patients group had a history of defoliant exposure while the control group did not. Among the 401 victims studied, a total of 110 patients were male out-of-hospital cardiac arrest patients. Baseline characteristics and the parameters involved in cardiac arrest were analyzed and compared between the two groups after propensity score matching. The primary outcome was survival to discharge, and secondary outcomes were sustained return of spontaneous circulation (ROSC) and survival to admission. Results: After propensity score matching a total of 50 patients (case=25, control=25) were analyzed. Primary outcome (survival to discharge) was not significantly different between case and control groups [(OR, 1.759; 95% C.I., 0.491-6.309) and (OR, 1.842; 95% C.I., 0.515-6.593), respectively]. In the subgroup analysis, there were also no significant differences between the control group and subgroups in primary and secondary outcomes according to defoliant exposure severity. Conclusion: There is no statistically significant association between defoliant exposure and survival of out-of-hospital cardiac arrest.

내부자거래와 이익조정

김문철 ( Moon Chul Kim ),전영순 ( Young Soon Cheon ),이정엽 ( Jung Youp Lee ) 한국회계학회 2010 會計學硏究 Vol.35 No.4

본 연구에서는 내부자거래와 관련된 이익조정동기를 살펴본다. 구체적으로, 기업의 내부자가 보유 중인 자사 주식을 보다 높은 가격으로 처분하거나 자사 주식을 보다 낮은 가격으로 매입하기 위하여 이익조정을 행하는지를 실증적으로 분석한다. 내부자거래를 통해 이익을 얻고자 하는 경우에는 매도(매수)거래를 수행하기 전에 의도적으로 이익을 상향(하향)조정할 경제적 유인이 존재한다. 또한 이러한 이익조정동기는 정보비대칭이 심각한 경우에 보다 강하게 나타날 것으로 예상된다. 실증분석 결과, 재량적발생액은 해당 재량적발생액이 포함된 이익이 공시된 후에 수행된 내부자 매도거래와 양(+)의 관계를, 내부자 매수거래와는 음(-)의 관계를 보인다. 그러나 이러한 결과는 코스닥시장에서만 통계적으로 유의하다. 또한, 내부자거래 전의 이익조정은 소규모기업, 신생기업, 고성장기업 및 재무분석가의 수가 적은 기업 등 정보비대칭이 큰 기업에서 더욱 심화된다. 이는 기업과 투자자간의 정보비대칭이 클수록 기업에 대한 정보의 부족으로 투자자들의 재무정보 의존도는 큰 반면, 이익조정 여부가 발견될 가능성이 낮다는 점에서 경영자의 이익조정 동기가 더 강화되는 것으로 해석할 수 있다. 이러한 정보비대칭에 따른 특성도 주로 코스닥시장에서 유의하게 나타난다. 이는 유가증권시장에 비해 상장요건 및 규제 등이 상대적으로 덜 까다로운 코스닥시장에서, 특히 정보비대칭이 높은 경우에 경영자는 내부자거래 전에 의도적으로 이익을 조정함으로써 보다 유리한 조건으로 내부자거래를 수행하려는 유인이 있음을 보여준다. This study examines whether insiders manage earnings before engaging in insider trading. Earnings management, if successful in affecting stock prices either by increasing stock prices or delaying stock price decline, will benefit insiders from subsequent insider transactions. Thus, insiders have incentives to manage earnings prior to insider trading. Insiders who plan to sell their shares are likely to inflate earnings beforehand. In contrast, insiders will manage earnings downward when they intend to buy shares of their firm. We, therefore, hypothesize that insiders engage in income-increasing (income-decreasing) earnings management in the current period when they plan to sell (buy) shares of their firm in the subsequent period. Furthermore, information environment of the firm is likely to affect insiders` selfserving earnings management. Specifically, insiders of firms with lower information asymmetry are less likely to manage earnings because market participant could easily detect earnings management and thus it is difficult to boost stock prices by inflating earnings. In addition, opportunistic trading may involve significant potential costs to insiders such as regulatory intervention, bad reputation, and shareholder lawsuits. On the other hand, investors tend to more heavily rely on financial information disclosed by managers when there is little information available about the firm. Furthermore, it will be difficult for investors to detect and nullify earnings management when there is high information asymmetry between managers and investors. Thus, we expect that insiders of firms with high information asymmetry are more likely to manage earnings before engaging in insider transactions. To test for our hypotheses, we regress earnings management on insider trading variables and other control variables. We employ discretionary accruals as a proxy for earnings management. Discretionary accruals are estimated from the modified Jones model. Insider trading is measured in two ways. First, we measure insider trading as cumulative shares purchased (BUY) and cumulative shares sold (SELL) over the 6-month period after earnings announcements. The second measure is the net shares purchased (NST) which is the cumulative shares purchased less cumulative shares sold during the 6-month period after earnings announcements. We deflate all insider trading variables by the number of shares outstanding on the trading day. Also, we employ four proxies for information asymmetry--firm size, firm age, market-to-book ratio of shareholders` equity, and the number of analysts following. Our sample consists of 7,327 firm-years over 2000-2006 period. The findings of the study are as follows: First, consistent with our prediction, there is the negative association between discretionary accruals and net shares purchased (NST). Also, when we use BUY and SELL separately instead of NST, discretionary accruals are negatively associated with BUY, and positively associated with SELL. The regression results reveal that the negative relation between discretionary accruals and NST is significant only for KOSDAQ firms. Similarly, the negative relationship between discretionary accruals and BUY and the positive relation between discretionary accruals and SELL are salient only in KOSDAQ firms. These findings suggest that insiders of KOSDAQ firms tend to inflate earnings before selling shares of their firm and tend to manage earnings downward before buying shares of their firms. In contrast, earnings management prior to insider trading is not salient in the KOSPI market. In order to test for whether information asymmetry of the firm affects earnings management related to insider trading, we divide the sample into high- and lowinformation asymmetry groups and conduct separate analyses for each group. We classify the firm into the high information asymmetry group if the firm size is equal to or below the cross-sectional median, if the firm age is equal to or below the cross-sectional median, if the ratio of market value to book value of shareholders` equity is above the cross-sectional median, and if the number of analysts following the firm is equal to or below the cross-sectional median. We find income-increasing discretionary accruals before selling and income-decreasing discretionary accruals before buying only for firms with high information asymmetry. Also, this relationship is prominent in KOSDAQ firms. We are unaware of any research, using the Korean stock market data, that examines earnings management driven by insider trading incentives. Also, this study furthers the examination of the relationship between insider trading and earnings management by investigating whether information asymmetry between managers and investors aggravates earnings management motivated by insider trading. Our results provide useful implications for investors, regulators, and auditors. Investors may consider the possibility of earnings management in the presence of frequent insider trading when they evaluate the quality of financial information. Also, the fact that earnings management prior to insider trading is salient in KOSDAQ firms with high information asymmetry calls for regulatory actions to reduce information asymmetry in these firms.