• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.341-356
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• 2007

We study factors that affect consumers' switching behaviors among service providers in Korean mobile telecommunications service market. For empirical analysis, quarterly time series data from the first quarter of 2004 through the second quarter of 2007 were used. We chose the number of switchers to each mobile service provider in each quarter as dependent variables. Independent variables include acquisition costs per subscriber, which play the role of subsidy to mobile handset, switching costs, time trend, structural change effect, and standby demand effects. Through the empirical analysis, we found that different providers' churn-in customers are affected by different factors. Specifically, the number of chum-in customers into SK Telecom is explained mainly by SK Telecom's customer acquisition costs and standby demand from KTF, while the number of customers switching into KTF is better explained by switching costs from the previous service provider and standby demand from SK Telecom. Those who chose LG Telecom as their new provider, on the other hand, were mainly attracted by LG Telecom's high subscriber acquisition cost.

• Journal of Technology Innovation
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• v.24 no.3
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• pp.81-105
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• 2016

The purpose of this study is to estimate the cost-saving effect of R&D investment in the ICT industry. As is well known, the R&D investment induces both the product innovation and the process innovation, in turn leads the effect of creating profit and cutting cost. However, it appears that studies concerned with the cost-saving effect of R&D investment have been unproductive, while most existing studies concentrate on the topic involved with the creating profit of R&D investment. Therefore, we extend the effect of R&D investment to a framework of the cost-saving focusing on the ICT industry. To empirically analyze the effect, we built a simultaneous three-equation model comprising a translog cost function and two cost share equations, and employed the SUR analysis. As a result, we found out that the cost-saving effect on the total cost is statistically significant. In addition, we examined relationships between the R&D investment and each cost of production elements. The results show that on the one hand, the R&D investment and the intermediate good cost have the substitution relationship. On the other hand, the complementary relationship is observed between the R&D investment and each labor or capital cost.

• Korean Journal of Agricultural Science
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• v.32 no.1
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• pp.81-94
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• 2005

This study is aimed at giving the basic information for individual farm households to make decisions for optimizing their farm sizes and for the government to implement farm size optimization policies through the identification of combinations among rice production factors in plain areas like Cheolwon district and the suggestion of the optimal farm sizes of individual farmers based on the scale of economy calculated. The data of agricultural production costs of 50 rice farmers in the plain area which is located in Dongsong-eup Cholwon district, Kangwon province were used in the analysis. The 'translog' cost function among various methods which is a flexible function type was adopted to calculate the scale of economy in rice production. Seemingly unrelated regression(SUR) method was used in forecasting functions and processing other statistics by SHAZAM which is one of the computer aid program for quantitative econometric analysis. In conclusion, the long-run average cost(LAC) curve showed 'U-shape' which was different from 'L-type' one which was shown in the previous studies by others. The lowest point of the LAC was 9.764ha and the concerned production cost amounted to 633 Won/kg. Based on these results, it have to be suggested that around 10 ha of paddy is the target size for policy assistances to save costs under the present level of farming practices and technology. The above results show that the rice production costs could be saved up to 10ha in Cheolwon plain area which is a typical paddy field. However, land use, land condition, land ownership and manager's ability which may affect scale of economy should be considered. Furthermore, reasonable management will have to be realized by means of labor saving technology and cost saving management skill like enlargement of farm size of rice.

• Journal of Korea Technology Innovation Society
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• v.21 no.4
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• pp.1508-1535
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• 2018

Employment in enterprises is a consecutive decision-making process based on the results of their innovative activities and it is necessary to consider this relationship as well explicitly in an analysis of the employment performance through technological innovation. Based on this critical mind, this study would analyze the structural relationships among enterprises' innovative activities, the performance of technological innovation, a compensation system and the creation of employment, reflecting the correlation of the process of the actual technology management performed simultaneously, utilizing the seemingly unrelated regression(SUR) model to estimate a simultaneous equation in addition to analyzing the relationship between technological innovation and the effect on employment with the ordered logit model to estimate a single equation as in the preceding studies. As a result of the analysis, a structural relationship could be found out, in which the execution of the compensation system would increase the performances of technical development and technology commercialization, which in turn, accelerates enterprises' employment. Especially, it is judged that enterprises' employment performance increases when technological innovation is managed from a process perspective in that the commercialization performance, as well as technical development, acts as a kind of hurdle in the effect on employment.

• Journal of Korean Society of Transportation
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• v.25 no.6
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• pp.141-157
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• 2007

This paper evaluates the effects of privatization and deregulation on the firm-specific efficiency and total factor productivity (TFP) growth in the Korean and Japanese railways. Using a stochastic frontier approach and a generalized translog functional form, the paper specifies the equation system consisting of a multiproduct variable cost function and input share equations which is estimated with Zellner's iterative seemingly unrelated regression and the corrected least squares method. The Korean and Japanese railway firms are assumed to produce three outputs (Shinkansen passenger-kilometers, incumbent railway passenger-kilometers, ton-kilometers of freight) using three input factors (labor, fuel, maintenance and rolling stock). A monetary value of the ways and fixed installations held by the railroad firm is also included as a quasi-fixed input. The empirical results indicate that the average estimate of cost inefficiency is 2.57% for the total sample and on the average, JNR and JR Kyushu are found to be worst efficient while the most efficient railway firm in the sample is JR West. Also the cost efficiency levels of seven JRs have been improved after the reform and privatization of JNR. The findings also indicate that TFP growth of the privately-owned JRs are higher than those of the government-owned KNR and JNR. Three-island JRs and JR Freight have slightly higher TFP growth than Honshu JRs as well. Thus, the results suggest that managerial autonomy and increased competition via deregulation have improved efficiency and TFP growth.

• Journal of Korea Technology Innovation Society
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• v.10 no.3
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• pp.383-405
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• 2007

In this paper we estimate knowledge production function for 15 South Korean industry sectors using panel data. To accommodate the influence of inter-sectoral interactions on the creation of knowledge, we estimate parameters for related knowledge production functions using the Dynamic Seemingly Unrelated Regression(DSUR) model proposed by Mark et al. (2005). We find the elasticity of knowledge production with respect to the size of research staff to be 0.25 and that with respect to the existing stock of knowledge to be 0.35. The fact that the elasticity of new knowledge creation with regard to the existing knowledge stock is below 1 in South Korea corroborates the view that the rate of long-term growth of her economy is chiefly determined by the elasticity related to production functions of goods and services and the rate of population growth, and that her government policy, to ensure a continued growth for the Korean economy, must shift the focus of R&D policies from the current direct intervention-centered model to one consisting of indirect measures, namely supporting knowledge management and diffusion and the creation of a knowledge sharing system. In terms of R&D policy implications it could be consider that the national knowledge production system should strengthen the cumulative process of knowledge accumulation and population for research and development. Our country R&D policy, also, need to adopt a global approach to increase knowledge stock at the highest levels of a country.

• KDI Journal of Economic Policy
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• v.27 no.2
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• pp.239-251
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• 2005

This paper investigates the effectiveness of economic policy on the stock market in Korea around foreign currency crisis and stock market opening. For this purpose, the paper applied SUR technique to a set of monthly data over the period 1982.01 to 2004.12. The study finds the following results. First, for the entire sample period, Korean stock market appears to have effectively incorporated all of the past information about fiscal policy moves. However, the paper finds an evidence that some of the past monetary actions have significant impacts upon current stock returns implying that the information about past monetary moves has been overlooked. Second, there is an evidence to suggest that, after foreign currency crisis, the macro economic policy actions may influence stock market in a different way. In particular, after foreign currency crisis, monetary policy influences stock market in a more delayed pattern while past fiscal policy moves are well incorporated into current stock returns. Third, before stock market opening to foreign investors, some of the past economic policy actions have significant effects on current stock returns. On the contrary, after stock market opening, none of the past macro economic information has significant impact upon current stock returns. The results imply that stock market opening may contribute to the active utilization of economic information for market participants in Korea.

• Journal of Distribution Science
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• v.14 no.10
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• pp.93-107
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• 2016

Purpose - This study aims to derive directions and implications for improving performance in operating agrifood export organizations by identifying significant performance impact factors. Research design, data, and methodology - A seemingly unrelated regression (SUR) model was estimated using data from a survey conducted among 120 exporters including 16 leading export organizations. In the SUR estimation, the export volume and price are used as dependent variables and securing the quantity of products ordered and exported, quality management, and marketing activities are considered as explanatory variables for the operation performance. Results - The amount of farmer education, the manpower in charge of marketing, and the interaction terms between whether or not they belong to a leading export organization and the item dummy for mushrooms have a significant impact on the export volume where the export volume is specified as a dependent variable. The export volume is greater with a greater amount of farmer education and greater manpower in charge of marketing from the perspective of quality management. When the export price is estimated as a dependent variable, the manpower in charge of marketing is shown to have a significant impact on the export price. Conclusions - The government needs to strengthen its support of the performance of agrifood export organizations. The analysis indicates that the education of and consulting with farmers, and the manpower number in charge of marketing are key factors in the operation performance of export organizations. Therefore, supporting the export organizations in expanding their human resources in charge of marketing can increase the export volumes for agrifoods. Given, however, that the export volume associated with joint payments, human resources specialized in quality management, and the amount of participation in export exhibitions are not significant factors, it is essential to improve the supporting policies for those areas. The manpower in charge of marketing from the perspective of marketing has a significant impact on both the export volume and export price. Thus, we identify this as the most important category that should be supported to enhance performance in export organizations.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.159-173
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• 2004

Using a generalized translog multiproduct cost function model, this paper examines economies of scale and scope in the vertically-integrated Korean railway industry. The paper then conceptualizes that the Korea National Railroad (KNR) produces four outputs (passenger-kilometers, ton-kilometers of freight, average length of passenger trips, and average length of freight haul) using three input factors(labor, fuel and maintenance, and rolling stock and capital). Using time series data collected from the KNR's annual records for the years from 1977 to 2002, the simultaneous equation system consisting of a cost function and two input share equatins is estimated with the Zellner's iterative seemingly unrelated regression. The findings show that the cost function corresponding to a non-Cobb-Douglas, non-homothetic, and non-homogeneous production technology adequately represents the KNR's cost structure. On the other hand, the Korean railway industry experiences sizeable overall scale economies, which result from substantial product-specific scale economies associated with passenger-kilometers and freight ton-kilometers and from scope economies associated with their joint production. In addition, the magnitude of economies of scope is influenced largely by the ratio of passenger trips, and has increased over time as the former has increased while the latter has decreased.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.65-78
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• 2006

This paper investigates the cost structure ot the Korea and Japan railroad industry with respect to density, scale and scope economies as well as productivity growth rate using a generalized trans)og multiproduct cost function model. The paper then assumes that the Korea and Japan railway companies pi·educe three outputs (incumbent railway passenger-kilometers. Shinkansen passenger-kilometers, ton-kilometers of freight) using four input factors (labor, fuel, maintenance, rolling stock and capital). The specified cost function includes foul other independent variables: track lengths to reflect network effects, two dummies to reflect nation and ownership effects, and time trend as a proxy for technical change. The simultaneous equation system consisting of a cost function and three input share equations is estimated with the Zellner's iterative seemingly unrelated regression. The unbalanced panel data used in the paper, a total of 154 observations. are collected from the annual records of the Korea National Railroad (KNR) for the yews $1977{\sim}2003$, Japan National Railways (JNR) for the years $1977{\sim}1984$. seven Japan Railways (JR's) for the years $1987{\sim}2003$. The findings show that the Korean and Japanese railways exhibit product-specific and overall economies of density but product-specific diseconomies of scale with respect to incumbent railway passenger-kilometers, Shinkansen-kilometers and ton-kilometers. However, the railways experience mild overall economies of scale which result from economies of scope associated with the joint production of incumbent railway/Shinkansen and feight, freight/incumbent railway and Shinkansen except Shinkansen/incumbent railway and freight. In addition, the economies of density and scale in the KNR, JR east, JR central, and JR west companies at the point of the years $1990{\sim}2003$ average is generally analogous to the above results at the point of sample average. There also appear to be economies of ssope associated with the joint Production of the incumbent railway and Shinkansen in JR central but diseconomies of scope in JR East and JR West. The findings also indicate that the productivity growth rate of the privately-owned JR's is larger than that of the government-owned KNR.