• KDI Journal of Economic Policy
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• v.31 no.2
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• pp.47-85
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• 2009

With a relatively simple quantitative method, this study comprehensively analyzes the characteristics related to business cycles represented by macroeconomic variables of Korea since 1970. This empirical analysis deals with roughly following three topics: How to identify cyclical component with respect to trend; with what characteristics and how the economic variables of each sector move with in the phases of business cycle, and; whether there are signs of a structural change in the phases of business cycle. Section 2 discusses how to identify trends and cycle components, the basis assumption for the analysis of business cycle. Like the Korean economy, where a relatively high growth rate has been maintained, it is appropriate to determine its economic recession based on the fall in the growth trend, not in the absolute level of real output. And, it is necessary to apply the concept of growth cycle against a traditional concept of business cycle. Accordingly the setting of growth trend is of preliminary importance in identifying cyclical fluctuations. The analysis of Korea's GDP data since 1970, the decomposition of trends and cycles through the Band-pass filter is found to appropriately identify the actual phases of busyness cycle. Section 3 analyzes what particular relationship various economic variables have with output fluctuations during the phases of economic cycle, using the corss-correlation coefficients and prediction contribution. Section 4 monitors the stability of the phases of Korea's business cycle and quantitatively verifies whether there is a structural break, and then reviews the characteristics of variations in each sector. And, stylized facts observed through these studies are summarized in the conclusion. The macroeconomic stability of Korea, in particular, is found to continue to improve since 1970, except for the financial crisis period. Not only that, it is found that its volatility of economic growth rate as well as inflation have been reduced gradually. Meanwhile, until recently since 2000, the volatility in domestic demand has remained stable, while that in exports and imports has been increased slightly. But, in an over all perspective, Korea's business cycle variation is on the decline due to shorter response period to shocks and the formation of complementary relationship among economic sectors.

• KDI Journal of Economic Policy
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• v.35 no.4
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• pp.63-94
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• 2013

This study aims to understand the long-run movement of volatility in Korean stock market by decomposing stock volatility into the long-lived and the short-lived components. In addition, I analyze how the low-frequency movement of stock market volatility is related to changes in macroeconomic conditions. The volatility decomposition is made based on the GARCH-MIDAS model, in which the long-lived volatility is constructed based on the combination of realized volatilities (RVs). The results show that the long-lived volatility contains information of up to 3~4 years of past RVs. In addition, the changes in the long-lived volatility can explain about two thirds of volatility changes in the Korean stock market from 1994 to 2009. Meanwhile, the low-frequency movement in the market volatility can be related to changes in macroeconomic conditions. The analysis shows that the stock market volatility appears to be countercyclical while showing a positive correlation with the inflation. In addition, the stock market volatility tends to rise as macroeconomic uncertainty increases. These results imply that macroeconomic policies aiming at economic stabilization could contribute to reduction in the stock market volatility.

• KDI Journal of Economic Policy
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• v.13 no.2
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• pp.129-140
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• 1991

The primary purpose of price regulation on public utilities and other public services is not to prevent them from rising and control inflation but to allocate resources efficiently and reflect social values, when market does not function perfectly. That is, price regulation by government is a policy tool which is aimed at microeconomic effects. Therefore, when a microeconomic policy tool is used for macroeconomic policy objectives, such as price stabilization, we can have problems stemming from the mismatch. One of the examples is distortions in the relative price structure of resources. As government suppresses increases in regulated prices in an effort to reduce inflationary pressures, some of the public services become relatively cheaper, resulting in excess use of those services under regulation. Also, inflexibility of adjusting regulated prices to the overall price changes results in deterioration of qualities of public services. This paper proposes a set of reform proposals which are itnended to minimize such government failures. It is argued that the authority of price regulation should be decentralized, and ultimately done by independent regulatory commissions for each service. The pricing should be based on the principle of separate and independent accounting by each service unit and the principle of beneficiaries bearing the costs of services.

• Journal of the Korean Data and Information Science Society
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• v.28 no.3
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• pp.493-504
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• 2017

We often observe count data that exhibit over-dispersion, originating from too many zeros, and under-dispersion, originating from too few zeros. To handle this types of problems, the zero-altered distribution model is designed by Ghosh and Kim in 2007. Their model can control both over-dispersion and under-dispersion with a single parameter, which had been impossible ever. The dispersion type depends on the sign of the parameter ${\delta}$ in zero-altered distribution. In this study, we demonstrate the role of the dispersion type parameter ${\delta}$ through the data of the number of births in Korea. Employing both the chi-square statistic and the Kolmogorov statistic for goodness-of-fit, we also explained any difference between the theoretical distribution and the observed one that exhibits either over-dispersion or under-dispersion. Finally this study shows whether the test statistics for goodness-of-fit show any similarity with the role of the dispersion type parameter ${\delta}$ or not.

• Management & Information Systems Review
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• v.37 no.2
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• pp.87-108
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• 2018

This article explores the international trade flow of Bangladesh's ready-made garments (RMG). We first suggest the brief history and an international structure of trade among countries by using the trade volume. Then we implemented a gravity model regression with the sample of 38 major partner countries in order to investigate the potential export market for the RMG industry. The fixed effect and random effect model for the panel data during the period of 1990 to 2011 are estimated. Our result shows that Bangladesh's RMG exports are affected positively by the size of economy, inflation, exchange rate, foreign direct investment(FDI) and trade openness. On the other hand, the distance between trading partners are related negatively with the trade volume. We used the estimated coefficients from the panel regression in order to predict RMG export potential of Bangladesh. This might show which country is the promising export market for Bangladesh RMG industry. We found that Bangladesh has the highest potential of RMG export with Japan and USA, which seem to have considerable room for export growth if trade barriers and constraints are removed. We added some policy implications for encouraging the RMG export of Bangladesh by using the results from the analysis.

• Journal of Preventive Medicine and Public Health
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• v.51 no.2
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• pp.83-91
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• 2018

Objectives: One of the main objectives of the Targeted Subsidies Law (TSL) in Iran was to improve equity in healthcare financing. This study aimed at measuring the effects of the TSL, which was implemented in Iran in 2010, on equity in healthcare financing. Methods: Segmented regression analysis was applied to assess the effects of TSL implementation on the Gini and Kakwani indices of outcome variables in Iranian households. Data for the years 1977-2014 were retrieved from formal databases. Changes in the levels and trends of the outcome variables before and after TSL implementation were assessed using Stata version 13. Results: In the 33 years before the implementation of the TSL, the Gini index decreased from 0.401 to 0.381. The Gini index and its intercept significantly decreased to 0.362 (p<0.001) 5 years after the implementation of the TSL. There was no statistically significant change in the gross domestic product or inflation rate after TSL implementation. The Kakwani index significantly increased from -0.020 to 0.007 (p<0.001) before the implementation of the TSL, while we observed no statistically significant change (p=0.81) in the Kakwani index after TSL implementation. Conclusions: The TSL reform, which was introduced as part of an economic development plan in Iran in 2010, led to a significant reduction in households' income inequality. However, the TSL did not significantly affect equity in healthcare financing. Hence, while measuring the long-term impact of TSL is paramount, healthcare decision-makers need to consider the efficacy of the TSL in order to develop plans for achieving the desired equity in healthcare financing.

• Journal of fish pathology
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• v.11 no.2
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• pp.97-104
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• 1998

Since 1989, mass mortality has repeatly occurred in cage-cultured sevenband grouper, Epinephelus septemfasciatus along the southern coast of Korea in the summer season and usually reached over 80% within a few months. Diseased fish showed the clinical signs of anorexia, dark coloration, loss of eqilibrium, spinal swimming behaviour, vertebral deformity and inflation of swim bladder. Histopathologically, necrosis and/or vacuolation of the nerve cells in the brain and retina were observed. We previously reported that the causative agent was filtrable. The causative agent was not culturable in various fish cells; RTG-2, CHSE-214, BF-2, EPC and FHM. However, electron microscopic observation revealed unenveloped icosahedral viral particles with about 30 nm in diameter in the cytoplasm of nerve cells of the brain. The characteristics of the virus was tested by an artificial infection with the filtrate of the homogenate of diseased fish. The pathogenicity of the virus was retained after treatment with ether or heat ($50^{\circ}C$, 30 min) but partly lost by pH 3 or 11 treatment. These results suggest that the causative agent are similar to the fish nodavirus. In order to compare the causative agent with a fish nodavirus, Striped Jack Nervous Necrosis Virus (SJNNV), a polymerase chain reaction (PCR) was performed with primers specific to SJNNV. As a result, about 430 by PCR products were detected from the brain and the eye of both naturally and artificially infected sevenband grouper. All these results represent that the mass mortality in the cultured sevenband grouper is caused by the infection of a nodavirus similar to SJNNV and this is the first report of a fish nodavirus from the cultured sevenband grouper in Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.170-177
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• 2017

The price of land in Jeju is reaching a new high every day and this phenomenon not only causes real difficulties for the purchase of real estate by local residents, but also results in psychological deprivation. Therefore, this study analyzes the factors causing the increase of the land price in Jeju, in order to examine the measures required to stabilize the land price which is continuously rising. As a result of this study, we developed a land price prediction model including seven variables, including the 'inflation rate', 'interest rate', and 'population'. According to the model, land prices in Jeju are expected to rise steadily, and it is predicted that in 2020 the price will increase to 170% of that in 2015 and will triple by 2025. Based on the results of this study, this study suggested policy alternatives, such as 'Establishing a tourism policy for managing the number of tourists' and 'increasing the approval standards for development activities'. The two policies proposed in this study can be implemented as a regional initiative, which may be less effective than the changes in the national system, but it is meaningful that the efforts to stabilize the land price will continue at the regional level.

• Journal of Nutrition and Health
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• v.39 no.1
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• pp.35-43
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• 2006

This study aimed to evaluate the effect of dietary fiber supplementation with snack type on functional constipation. We conducted a double blind case-control study with 3 groups; placebo, low dose group (LD: insoluble fiber 7 g/d + soluble fiber 1.2 g/d) and high dose group (HD: insoluble fiber 14 g/d + soluble fiber 2.4 g/d) , which were randomly assigned out of subjects with functional constipation, defined by modified Rome II criteria. We measured anthropometric parameters and evaluated the bowel movement frequency, stool type, straining, sense of complete evacuation, abdominal discomfort/pain, abdominal inflation, relief and colon transit time before, during the supplementation. Both LD and HD groups had significant improvement in straining, sense of complete evacuation and satisfactory relief compared with placebo group (p < 0.05). When subdivide by baseline colon transit time (less than 24 hrs/ 24 hrs or more and less than 72 hrs / 72 hrs or more), only HD group had significantly improvement; colon transit time recovered near by 24 hrs in subjects of 'less than 24 hrs' (from $7.57{\pm}1.40$ hrs to $25.2{\pm}3.91$ hrs, p < 0.01) and reduced in those of '24hr or more and less than 72 hr' (from $47.0{\pm}3.36$ hrs to $31.3{\pm}4.31$ hrs, p < 0.01) and '72 hr or more' (from $106.7{\pm}10.7$ hrs to $85.0{\pm}13.1$ hrs, P < 0.05) subjects. Particularly, positive effect of fiber supplementation on straining and sense of complete evacuation in test groups seemed to be greater in subjects of '24 hrs or less' and '24 hrs or more and less' than 72 hrs' than those of '72 hrs or more'. In conclusion, subjects with functional constipation, particularly those having colon transit time less than 72 hrs can significantly improve, at least in part, symptom related to constipation by fiber supplementation of snack type without serious side effects.

• The Korean Journal of Applied Statistics
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• v.33 no.3
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• pp.335-345
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• 2020

This paper deals with the problem of estimating the log-transformed linear regression model to fit actual battle data from the Ardennes Campaign of World War II into the Lanchester model. The problem of determining a global solution for parameters and multicollinearity problems are identified and modified by examining the results of previous studies on data. The least squares method requires attention because a local solution can be found rather than a global solution if considering a specific constraint or a limited candidate group. The method of exploring this multicollinearity problem can be confirmed by a statistic known as a variance inflation factor. Therefore, the Lanchester model is simplified to avoid these problems, and the combat power attrition rate model was proposed which is statistically significant and easy to explain. When fitting the model, the dependence problem between the data has occurred due to autocorrelation. Matters that might be underestimated or overestimated were resolved by the Cochrane-Orcutt method as well as guaranteeing independence and normality.