An One-factor VaR Model for Stock Portfolio (One-factor 모형을 이용한 주식 포트폴리오 VaR에 관한 연구)
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- The Korean Journal of Applied Statistics
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- v.26 no.3
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- pp.471-481
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- 2013
The current VaR Model based on J. P. Morgan's RiskMetrics has problem that actual loss exceeds VaR under unstable economic conditions because the current VaR Model can't re ect future economic conditions. In general, any corporation's stock price is determined by the rm's idiosyncratic factor as well as the common systematic factor that in uences all stocks in the portfolio. In this study, we propose an One-factor VaR Model for stock portfolio which is decomposed into the common systematic factor and the rm's idiosyncratic factor. We expect that the actual loss will not exceed VaR when the One-factor Model is implemented because the common systematic factor considering the future economic conditions is estimated. Also, we can allocate the stock portfolio to minimize the loss.
This case study investigates the KIKO currency option that has been a social issue in recent years among developing countries, especially Korea, where the financial derivatives market is in a state of rapid growth. The forward transaction which becomes a basis of derivatives is intended to hedge risks that may be caused by a future change in asset prices. Although it originates from a simple form of agricultural transactions, there currently exists a variety of derivatives in more sophisticated forms. In the Korean agricultural industry, the need to use such derivatives is great, as there is a huge risk of price fluctuation in agricultural products due to frequent adverse weather. In addition, many developing countries with export-led industrial structures similar to Korea's, of necessity must resort to currency hedging as a method of reducing relevant risk. However, in most cases, the lack of understanding about financial derivatives results in an inappropriate application of these derivatives. The KIKO in this study represents such cases. Since 2007, KIKO has been sold in Korea to many small- and medium-sized export companies for the purpose of currency hedging when the exchange rate between the Korean won and the U.S. dollar was in a downward spiral. The main focus of this study is a case which is most representative of KIKO. As inflation rapidly increased during the financial crisis in the U.S. at the end of 2007, derivatives became a hot issue in the courts rather than in the financial markets. This case study investigates what KIKO and the fierce legal debates over it imply, from the perspective of the option of value evaluation in order to suggest not only a direction in which companies can utilize financial derivatives, but also a roadmap for the future derivatives market.
The purpose of this study is to investigate the effect of macro-finance variables on the correlation between the housing and stock markets because understanding the nature of time-varying correlations between different assets has important implications on portfolio allocation and risk management. Thus, we adopted the AG-DCC GARCH model to obtain time-varying, conditional correlations. Our sample ranged from January 2004 to November 2017. Our empirical result showed that the coefficients on asymmetric correlation were significantly positive, implying that correlations between the housing and stock markets were significantly higher when changes in the housing price and stock returns were negative. This finding suggested that the housing market has less hedging potential during a stock market downturn, when such a hedging strategy might be necessary. Based on the regression analysis, we found that the term spread had a significantly negative effect on correlations, while the credit spread had a significantly positive effect. This result could be interpreted by the risk premium effect.
Objectives: The purpose of this study is to analyze the content of N,N-dimethylformamide(DMF) in polyurethane coated gloves(PU-gloves) and to assess the dermal exposure generated by wearing them. Methods: We analyzed the concentrations of DMF in 12 gloves by EN16778 standard. The samples cut into pieces of about 10 by 10 mm and extracted with methanol in flask in an ultrasonic bath at 70℃. An aliquot of the extract is analyzed with GC-MS. The dose of dermal exposure was calculated by ECETOC TRA consumer 3.1 and compared with derived no effect level(DNEL) for systemic effects due to long term exposure by workers. The extracted amount of DMF by saline solution was compared with that by EN16778 standard. Results: The mean concentration of DMF in PU-gloves was 1,377 mg/kg(range 13~3,948 mg/kg). The concentration of DMF showed significantly differences by packing type, manufacturer, and price(p<0.05). The dose of dermal exposure was 0.0007~0.572 mg/kg body weight/day when the DMF content was 10~4,000 mg/kg. The DMF extracted by saline solution was around 11% for 8 hours. Conclusions: The risk of dermal exposure due to the residual DMF in the PU-gloves was not signifiant. But, the limit of 1,000 mg/kg in PU-gloves can be recommended for international standard and trading systems.
Franchising is one of the fastest growing types of business. It is already popular and well-known in the U.S., and has been growing in many other countries including Korea. Furthermore, many Korean franchising companies have expanded their business overseas actively. According to the data by the Ministry of Industry and Resource, 82 companies out of a sample of 500 franchising companies are already operating in many foreign countries and 48% of them have started their foreign business since 2006. This clearly indicates the fast growing current trend of foreign operation by Korean franchising companies. In spite of the fast growing trend of foreign expansion in the industry, academic research on internationalization of franchising companies is extremely difficult to find. Accordingly, academic research on the issue is necessary and urgent in Korea. Among the various research questions on internationalization of franchising business, this study intends to investigate the difference in organizational factors between the franchising companies doing foreign operation and those doing business only domestically. More specifically, this research has the following purposes. First, considering the lack of theoretical basis of previous studies, resource-based theory and agency theory are employed as the theoretical bases. Second, this study explains the difference in internationalization based on organizational factors such as company size, history and growth rate. Third, the five hypotheses regarding the difference in organizational factors are presented and tested empirically, which is the first attempt in the area of this topic. Finally, the study attempts to clarify the conflicting implications among theories regarding some organizational factos such as growth rate. As the theoretical background, resource-based theory and agency theory are discussed. According to resource-based theory, a firm can grow continuously when it has competence and resource, and also the ability to develop them. The competence and resource can include capital, human resource, management skill, market information, ability to manage risk, etc. Meanwhile, agency theory views the relationship between franchisor and franchisee as an agency relationship. In agency theory, bonding capability and monitoring capability are the two key factors which promote internationalization of franchising companies. Based on the two theories, a conceptual model is designed. The model consists of two groups of variables. One is organizational factors including size, history, growth rate, price bonding and geographic dispersion. The other is whether a franchising company is operating overseas or not. We developed the following five research hypotheses basically describing the relationship between organizational factors and internationalization of franchising companies. H1: The size of franchising companies operating overseas is larger than that of franchising companies operating domestically. H2: The history of franchising companies operating overseas is longer than that of franchising companies operating domestically. H3: The growth rate of franchising companies operating overseas is higher than that of franchising companies operating domestically. H4: The price bonding of franchising companies operating overseas is higher than that of franchising companies operating domestically. H5: The geographic dispersion of franchising companies operating overseas is wider than that of franchising companies operating domestically. Data for the analyses are obtained from 2005 Korea Franchise Survey data co-generated by Ministry of Industry and Resource, GS1 Korea, and Korea Franchise Association. Out of 2,804 population companies, 2,489 companies are excluded for various reasons and 315 companies are selected as the final sample. Prior to hypotheses tests, validity and reliability of the measures of size, history, growth rate and price bonding are examined for further analyses. Geographic dispersion is not validated since it is measured using nominal data. A series of independent sample T-tests is used to find out whether there exists any significant difference between the companies internationalized and those operating only domestically for each organizational factor. Among the five factors, size and geographic dispersion show significant difference, growth rate and price bonding do not reveal any difference and, finally, history factor shows conflicting results in the difference depending on how to measure it.