• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.6
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• pp.1207-1217
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• 2013

This study utilizes raw data from "Research on the actual condition of firms' information security" of KISA (2010) and constructs panel dataset to analyze a causal relationship between information security investment and security breach. Using Difference in Difference estimation method we find the following results. First, while the usual causality that information security investment reduces security breach is not supported, the reverse causality that security breach increases information security investment is well explained. Second, contrary to the conventional wisdom, firms in the finance/insurance business sector show the most significant reverse causality pattern.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.2
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• pp.523-531
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• 2016

This paper studies the empirical relationship between various privacy protection measures and personal information invasion experience of firms and individuals using rich and heterogeneous survey data. By analyzing PSM models. we get the following results: first, the treatment group which have more technical measures and/or IS investment tends to experience more privacy invasion than the control group which have less of them. second, the reverse causality, that is firms and individuals with more experience of privacy invasion tends to take more measure for personal information protection, is found to exist. From these result, we discuss proper privacy policies implications in respects of attackers benefits and individual irrationality.

• Asia Pacific Journal of Business Review
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• v.1 no.2
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• pp.1-16
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• 2017

The fundamental goal of the research was to verify if the Twin Deficits Hypothesis holds for the economy of Zambia using time series data from 1980-2014. The current account and budget deficit were employed as key variables. The exchange rate was also used as a transmission mechanism to see how it contributes in the nexus. Cointegration tests confirmed a long run association of the variables. After fitting the VECM model, Granger causality tests confirmed the existence of twin deficits for Zambia. The results supported uni-directional reverse causality. The exchange rate was shown to be more significant in the long run than in the short run. The implosion of the time series as shown by the predicted cointegration equation implies that unless drastic measures are taken to cure the deficits, using the current account as the major target variable, twin deficits will persist for some time. The major policy implication of this research is that given that Zambia is a primary commodity-dependent developing country subsisting largely on copper revenues to sustain the economy, there is a need to move away from "copper addiction," given the recent volatility of earnings of primary commodities (e.g. through diversification of the economy, import substitution, and other strategies).

• Environmental and Resource Economics Review
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• v.24 no.4
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• pp.629-655
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• 2015

Nuclear power generation is a major power source which accounts for more than 30% of domestic electricity generation. Electricity market needs to secure stability of base load. This study aimed at analyzing relationships between nuclear power generation and wholesale electricity price (SMP: System Marginal Price) in Korea. For this we conducted ARDL(Autoregressive Distributed Lag) approach and Granger causality test. We found that in terms of total effects nuclear power supply had a positive relationship with SMP while nuclear capacity had a negative relationship with SMP. There is a unidirectional Granger causality from nuclear power supply to SMP while the reverse was not. Nuclear power is closely related to SMP and provides useful information for decision making.

• Environmental and Resource Economics Review
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• v.26 no.4
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• pp.473-498
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• 2017

This study examines the effect of environmental regulation considering the endogeneity on the productivity of Korean manufacturing industry based on the Porter hypothesis using data from the Mining and Manufacturing Survey, Survey of Research and Development in Korea, and Environmental Statistics Portal from 2003 to 2013 with fixed effect model. In order to eliminate the bias of the missing variables that may occur in the existing studies, we analyze factors affecting productivity such as market competition, R&D investment as explanatory variables. And, in order to eliminate measurement error and inverse causality, we use instrumental variable approach. The main results are as follows. First, our findings that the environmental regulation improve the productivity of Korean manufacturing in the long-run support the Porter hypothesis. Second, our findings suggest that measurement error and reverse causality are main sources of the endogeneity, while omitted variable is not. Finally, environmental technology R&D has reduced productivity in the short-run.

• Korean Circulation Journal
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• v.53 no.7
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• pp.472-479
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• 2023

Background and Objectives: The association between bilirubin and atrial fibrillation (AF) has been evaluated previously in observational studies but with contradictory results. This study evaluated the causal association between serum bilirubin level and AF using Mendelian randomization (MR) analysis. Methods: This cross-sectional study includes 8,977 participants from the Dong-gu Study. In the observational analysis, multivariate logistic regression was performed to evaluate the association between bilirubin and prevalent AF. To evaluate the causal association between bilirubin and AF, MR analysis was conducted by using the UGT1A1 rs11891311 and rs4148323 polymorphisms as instrumental variables. Results: Elevated serum bilirubin levels were associated with an increased risk for AF in observational analysis (total bilirubin: odds ratio [OR], 1.31; 95% confidence interval [95% CI], 1.15-1.48 per 1 standard deviation [SD]; direct bilirubin: OR, 1.31; 95% CI, 1.18-1.46 per 1 SD), whereas the genetically predicted serum bilirubin levels in MR analysis did not show this association (total bilirubin: OR, 1.02; 95% CI, 0.67-1.53 per 1 SD; direct bilirubin: OR, 1.03; 95% CI, 0.61-1.73 per 1 SD). Conclusions: Genetically predicted bilirubin levels were not associated with prevalent AF. Thus, the observational association between serum bilirubin levels and AF may be noncausal and affected by reverse causality or unmeasured confounding.

• 한국노년학
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• v.37 no.4
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• pp.871-891
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• 2017

The purpose of this paper is to reduce the reverse-causality and overestimate bias of analysis on how health affected middle-aged and elderly worker's early retirement. From the Korean Longitudinal Study of Ageing(KLoSA) panel data, I researched 1,049 people who were 45-52 years old in 2006. To eliminate the reverse-causality problem, I used the health data which is surveyed before retirement. To reduce bias, I controlled the health status when retirees worked. The main results are as follows. First, the worsened health still affects the hazard of early retirement, with reducing the endogeneity problem. Second, chronic illness is one of the strong predictors of early retirement to self-employed, and self-reported bad health is the main health predictor of wage workers. These results give two implications; first, the impact magnitude of the health indicator depends on employment type. Each employment type has different flexibility of working hours. It seems that the flexibility can reduce early retirement hazard with health problems. Self-employed, who has more flexibility of working hours can work until they have to stop working due to the serious health problem or doctor's advice. Second, to promote middle-aged and elderly workers to keep working, the long-term health policy which decreases chronic illness is needed.

• The Journal of Asian Finance, Economics and Business
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• v.1 no.3
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• pp.5-16
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• 2014

This study aims to examine the dynamics of price changes and trading volume of Kuala Lumpur Options and Financial Futures Exchange (KLOFFE) from 2000 to 2008. With augmented analysis, our results support two hypotheses. First, under information spillover, our findings support noise traders' hypothesis as the time span for variance of past trading volume to cause variance of current return is found to be asymmetric under bull and bear markets. Second, looking at the dynamic relation between volume and volatility of price changes, our findings support Liquidity-Driven Trade hypothesis as past trading volume and subsequent volatility of return exhibit positive correlation. In terms of investors' behavior in response to the news, we find that investors are more risk taking in bull market and more risk reverse in bear market. Our study suggests that investors should adjust their strategy in the futures market in a dynamic manner as the time span of new information arrival is not consistent. Also, uninformed investors with information asymmetry should expect noninformational trading from informed investors to establish their desired positions for better liquid position.

• Journal of the Korean Home Economics Association
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• v.50 no.5
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• pp.25-38
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• 2012

Drawing on social and cultural capital theory, the study investigates the influences of social capital and cultural capital on the academic achievement of children in out-of-home care. We collected data from 494 children living in out-of-home services, including institutional care facilities, foster care homes, and group homes. To analyze the collected data, a multiple regression analysis method was used. In addition, the IV (instrumental-variables) estimation was utilized to rule out the possibility of reverse causality. The level of children's social capital was measured through children's relationships with parents and friends, parental monitoring, etc. The level of children's cultural capital was measured by their cultural activities, such as going to museums, and playing musical instruments. Children's personal characteristics and placement history in out-of-home services were used as control variables. We found that among personal characteristic variables, self-esteem, depression and anxiety, and delinquency affected the academic achievement of the children. Cultural capital, but not social capital, positively affected the level of academic achievement of the children. Based on the study results, implications for child welfare practice were discussed.

• Korea Trade Review
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• v.44 no.5
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• pp.143-159
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• 2019

This study explores the relationship between outward foreign direct investment (FDI) and innovation in 61 industries of Korea between 1999 and 2016. In order to mitigate the endogeneity problem due to potential reverse causality between FDI and innovation, we use the GMM (generalized method of moments). Our results are as follows. First, FDI has a positive effect on innovation. A possible explanation is that through FDI, multinational companies may assimilate host countries' technologies and knowledge by learning, and then recreating new technologies. Furthermore, this positive effect appears greater, as industrial competition becomes fiercer. This result provides empirical evidence that by recreating technology and knowledge learned through FDI with their own intangible assets, such as patents, they may gain a competitive edge over competitors. Second, this study confirms the greater positive effects of FDI in developed countries, as well as countries with higher technology levels. Finally, strategic asset seeking FDI has the greatest positive impact on innovation in Korean industries. In summary, our findings provide empirical evidence that Korean multinationals can learn technology and knowledge of host countries through FDI to secure a competitive edge in the Korean market.