• Environmental and Resource Economics Review
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• v.12 no.4
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• pp.559-577
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• 2003

This paper analyzes household bottled water and water purifier expenditures, taking into account three important characteristics: expenditures may be censored at zero, may be interdependent across expenditure type, and may be endogenously and jointly determined. Censoring, interdependence, and endogeneity of the two expenditures are examined through simultaneous equation bivariate Tobit model. Expenditure function parameters are estimated using a 1997 household survey data collected in Seoul. The study detected interdependence between the two expenditures in the data. Moreover, the coefficient of one expenditure variable is statistically significant in the other expenditure equation. Thus, the overall results show that the simultaneous equation bivariate Tobit model employed here is appropriate for this analysis of the two expenditures. Finally estimated income and household size elasticities of the expenditures are presented.

• Journal of Korea Port Economic Association
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• v.24 no.4
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• pp.349-361
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• 2008

There has been abundant empirical research undertaken on the technical efficiency of Korean ports. Most studies have focused on the use of parametric and non-parametric techniques to analyse overall technical efficiency. This paper utilizes data for the period 2000-07 to offer a heterogeneous perspective on the overall efficiency of Korean ports. The framework assumes that ports use one input to produce one output; the output and input include port export(import) and regional export(import). This paper also employs panel analysis and heteroscedastic Tobit model to show the effect of the explanatory variables on the port efficiencies. The panel analysis shows that the regional export/total export has negative effect on the export efficiency while the regional import/total import has not any relations with the import efficiency. The heteroskedastic Tobit model shows that both regional export ratio and regional import ratio have negative effects on the efficiency while the gross regional domestic product has not any significant relations with the import efficiency.

• The Korean Journal of Applied Statistics
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• v.27 no.6
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• pp.991-1002
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• 2014

Both Bayesian and maximum likelihood methods are efficient for the estimation of regression coefficients of various Tobit regression models (see. e.g. Chib, 1992; Greene, 1990; Lee and Choi, 2013); however, some researchers recognized that the maximum likelihood method tends to underestimate the disturbance variance, which has implications for the estimation of marginal effects and the asymptotic standard error of estimates. The underestimation of the maximum likelihood estimate in a seemingly unrelated Tobit regression model is examined. A Bayesian method based on an objective noninformative prior is shown to provide proper estimates of the disturbance variance as well as other regression parameters

• Journal of Information Technology Services
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• v.16 no.4
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• pp.15-31
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• 2017

This study analyzes 45 Korea IT service companies from 2012 to 2016 using DEA analysis. Large enterprises, medium enterprises and small and medium enterprises (SMEs). CCR model and BCC model were used for efficiency analysis. Among the various analytical objects, the decision objects which yield the maximum output with minimum input are compared with other analysis objects. The relative inefficiency was measured through this, and Technical Efficiency (TE), Pure Technology Efficiency (PTE), Scale Efficiency (SE), scale profit, reference frequency were analyzed. Also, we analyzed the Technology Gap Ratio (TGR), which is the distance between production function and Meta-Frontier for each firm, using Meta-Frontier analysis. Finally, the Tobit model is used to analyze the sources of efficiency and inefficiency. The inputs are assets, capital, and employees, and the output factor is sales. The analysis shows that large firms are achieving technological achievements more efficiently than small and medium enterprises. As a result, medium-sized enterprises and SMEs can improve efficiency overall through efficient operation of workforce and appropriate combination of inputs such as assets and capital. Also, as a result of the influence factor analysis, it was found that the ratio of the managed asset ratio and the management cost ratio were significant factors influencing the efficiency of the IT service companies. This study suggests the efficiency analysis using DEA for many Korea IT service companies. Inefficient parts of each company are classified according to size and technology. Also, we identify the most efficient companies and analyze the causes of those companies whose profits are lower than their size.

• Journal of Preventive Medicine and Public Health
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• v.40 no.2
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• pp.145-149
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• 2007

Objectives : This study characterized the extent to which youth depressive symptoms, parental alcohol problems, and parental drinking account for differences in alcohol-related problems among a large sample of adolescent females. Methods : The stratified sample consists of 2077 adolescent females from twelve female-only high schools located in a large metropolitan city in the Republic of Korea. Students completed a questionnaire about alcohol use and alcohol problems, their parents' alcohol problems, and a number of risk and protective factors. Data were analyzed using tobit regression analyses to better characterize the associations among variables. Results : Almost two-thirds of students who consume alcohol had experienced at least one to two alcohol-related problems in their lives and 54.6% reported at least one current symptom of depression, with nearly one-third reporting two depressive symptoms. Two-thirds of the students indicated that at least one parent had an alcohol-related problem, and that approximately 29% had experienced several problems. Results of tobit regression analyses indicate that youth alcohol-related problems are positively associated with depressive symptoms (p<0.01) and parent drinking problems (p<0.05). Parental drinking is no longer significant when the variable parental attention is added to the model. Decomposition of the tobit parameters shows that for every unit of increase in depressive symptoms and in parent drinking problems, the probability of a youth experiencing alcohol problems increases by 6% and 1%, respectively. For every unit of increase in parental attention, the probability of youth experiencing drinking problems decreases by 5%. Conclusions : This study presents evidence that alcohol-related problems and depressive symptoms are highly prevalent among adolescent females. Although a comprehensive public health approach is needed to address drinking and mental health problems, different interventions are needed to target factors associated with initiation of alcohol problems and those associated with increased alcohol problems among those who already began experiencing such problems.

• Journal of Digital Convergence
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• v.19 no.10
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• pp.339-348
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• 2021

This paper aims to analyze the production efficiency in Korea's ten service sectors using DEA and its determinants utilizing a truncated-Tobit regression model and a censored-Tobit regression model in 2010-2019. This paper found: First, the Korean service sector's production efficiency in general has been significantly low and polarized. Especially, the inefficiency resulted from the scale inefficiency in the 'sewerage waste management industry.' Second, in the determinants analysis, the results show the positive effect of the investment and R&D expenses on technical efficiency, while FDI and lobbying expenses illustrate the negative impact. Moreover, it seems that the larger the industry, the higher the efficiency. Thus, the future Korean government's economic policy for the service sectors requires a mixed and integrated policy of the macroeconomic aspect such as active investment and R&D activities with microeconomic aspect including a convergence of FDI and human capital.

• International Area Studies Review
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• v.13 no.3
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• pp.213-238
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• 2009

This paper empirically examines effects of exporting on employment over the period 2000-2007 for Korean listed and non-listed manufacturing firms. The paper employs the dynamic panel model of labor demand and controls for simultaneity of the exports and real wages using a two step random effect Tobit-DPD (Dynamic Panel Data) procedure. Our empirical results suggest that surprisingly, there is no robust evidence for employment effects of exporting of Korea's large firms and small-medium sized firms during the sample period after Korean financial crisis. This implies that Korean exporting patterns have been changed in a way that exporting highly capital intensive goods leads to importing more intermediate goods and thus to countervailing the employment effects of exporting. This suggests that expansion of exporting by lowering exporting prices through the bilateral FTA might not be helpful to enhancing employment in Korea.

• The Journal of the Korea Contents Association
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• v.19 no.2
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• pp.349-367
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• 2019

This paper empirically analyzed the factors of operational efficiency after the quasi-public bus operating system in Busan Metropolitan City. DEA analysis result, for CRS the annual efficiency in 2010 of bus routes that can be transferred to subway lines 1 was the highest. The annual efficiency of bus routes that can be transferred to subway lines 2 shows the largest annual average of 0.923 in 2016 under the CRS average gradually improved over the year. Annual efficiency of subway lines No. 3 and transferable bus routes gradually improved from 2009 to 2015, but declined again in 2016. Among 536 routes for four years on 134 routes per year, 205 routes were found to be inefficient. In order to increase efficiency of the 205 routes, it is suggested that the number of routes should be reduced. In addition, the analysis results on DEA using the Tobit calibration, the most significant factors affecting the operational efficiency index were the time taken, followed by the number of passengers and the number of passengers transferred.

• Journal of Industrial Convergence
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• v.15 no.2
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• pp.7-16
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• 2017

The 6th industrialization of agriculture, which promotes the virtuous cycle of creating new value with through the convergence integration of agriculture and contributing to the vitalization of local economy etc. Accordingly, the purpose of this research is to provide implication for the efficiency, vitalization of domestic 6th industrialization per regions Analysis is use of the "2015~2016 Food Agriculture 6th Industrialization Basic Reality Survey Research" report data. As an analytical method DEA(Data Envelopment Analysis), Tobit model were used for results. The following are the summary of hypothesis test. First, 6th industrialization of agriculture identify improve income growth and increase efficiency, Second, Efficiency influence factor analysis shows have a minus (-) relation that yearly rural population increase rate, and secondary industry participation rate. Third, 6th industrialization recognition of the business is plus(+) relation influenced. Through this research, There may be a limit of research data and qualitative factor etc, explanatory power, but it is meaningful in the sense that objective implication was drawn for the enhancement of the 6th industrialization per regions.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.361-374
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• 2021

The purpose of this study is to analyze the efficiency and productivity of technological innovation activities of companies certified as innovative pharmaceutical companies by the government to diagnose their competitiveness and derive measures to strengthen them. This study collected pharmaceutical input (R&D expenditures and number of employees) and output (sale, operating profit and patent) data between 2017 and 2019 for 38 innovative pharmaceutical companies. This study analyzed them using the data envelopment analysis (DEA) method, Tobit model and the Malmquist Productivity Index (MPI). First, the DEA result of the innovative pharmaceutical companies show that between the value of the CCR model of the scale efficiency and the value of the BCC model to diagnose the internal operation efficiency is differences. Second, efficiency does not differ between corporate characteristics. Third, Tobit model shows that number of patents held have positive effects on efficiency. Forth, overall MPI is 0.89. This can be interpreted as the rate of TECI decreased 3%p and TCI has increased 4%p. The results of this study can be used as decision-making data for response strategies to improve efficiency by identifying the cause of inefficiency and presenting target values.