• Communications for Statistical Applications and Methods
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• v.19 no.2
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• pp.293-301
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• 2012

Quantile regression proposed by Koenker and Bassett (1978) is a statistical technique that estimates conditional quantiles. The advantage of using quantile regression is the robustness in response to large outliers compared to ordinary least squares(OLS) regression. A regression tree approach has been applied to OLS problems to fit flexible models. Loh (2002) proposed the GUIDE algorithm that has a negligible selection bias and relatively low computational cost. Quantile regression can be regarded as an analogue of OLS, therefore it can also be applied to GUIDE regression tree method. Chaudhuri and Loh (2002) proposed a nonparametric quantile regression method that blends key features of piecewise polynomial quantile regression and tree-structured regression based on adaptive recursive partitioning. Lee and Lee (2006) investigated wage determinants in the Korean labor market using the Korean Labor and Income Panel Study(KLIPS). Following Lee and Lee, we fit three kinds of quantile regression tree models to KLIPS data with respect to the quantiles, 0.05, 0.2, 0.5, 0.8, and 0.95. Among the three models, multiple linear piecewise quantile regression model forms the shortest tree structure, while the piecewise constant quantile regression model has a deeper tree structure with more terminal nodes in general. Age, gender, marriage status, and education seem to be the determinants of the wage level throughout the quantiles; in addition, education experience appears as the important determinant of the wage level in the highly paid group.

• East Asian Economic Review
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• v.18 no.1
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• pp.29-54
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• 2014

The purpose of this research is to identify the relation between OFDI (Outward Foreign Direct Investment) and wage inequality. In order to analyze various effects of OFDI on wages depending on the types of workers, the research classified laborers into four categories: permanent/skilled worker, permanent/unskilled worker, temporary/skilled worker, and temporary/unskilled worker. With controlling wage-determining factors such as education, labor union, individual fixed-effect, and industry-level effect, this paper examines whether OFDI attributes to the wage inequality among each type of workers. Moreover, this study also analyzes possible effects on wages that could vary according to the different characteristics of investments by classifying OFDI into two groups: OECD and non-OECD. The results reveal that OFDI makes certain differences according to skill-intensity and contract type in terms of influences on wages. It also shows that the effect of OFDI on wages is more subject to contract type than to skill-intensity. The classification of OFDI into OECD and non-OECD proves that effects on wages can vary by characteristics of the subject of investment.

• Journal of Labour Economics
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• v.44 no.2
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• pp.71-90
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• 2021

This paper examines the effects of COVID-19 on the working hours and wages by employment types of wage workers. Using the Economically Active Population Survey-Supplementary Survey by Employment Types(2017-2020), I found that due to COVID-19, non-regular workers reduced their working hours more than regular workers, shrinking their opportunities to generate wage income. During the same period, the working hours and wage gap between new regular and non-regular workers widened, this was largely in part-time and short-term workers. As the working conditions change based on the initial level, these results show that efforts to improve their(new and short term workers) working conditions can contribute to mitigating labor market inequality.

• Journal of Digital Convergence
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• v.20 no.4
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• pp.1-14
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• 2022

The purpose of this study was to find the wage determinants of web-based platform workers. For this purpose, a total of 3,575 web-based platform workers' information from Freelancer.com, a global platform labor market, in September 2018 were used and whether or not newly available indicators such as evaluations by previous employers had a significant effect on the wage increase of platform workers using OLS and QR methods. As an OLS estimation results, the number of reviews, as well as education and experience, affects the wages of platform workers. However, as a result of the QR estimation, experience rather than education, recommendation rather than a review has a more significant effect on the wage of web-based platform workers as the wage level rises.

• 중국학논총
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• no.63
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• pp.205-224
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• 2019

The results of the studies of China and Vietnam are as follows. First of all, in China, the labor market in China has been fully completing laws and regulations since the implementation of the labor contract law in 2008. Specifically, we analyzed the labor market in China for labor contracts, recruitment, and minimum wage. Next, in Vietnam, which the tertiary and quaternary industries are rapidly developing. The labor market is expected to increase because demand for foreign manpower, as the advancement of retail, finance, tourism services, Smart factories in the textile and sewing- do. The limitations of this study, however, are that there is not enough data to utilize official data for labor market analysis in China and Vietnam. If a practical investigation is conducted for analyzing the labor market in Vietnam due to the changes in the labor market

• Journal of Labour Economics
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• v.27 no.1
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• pp.135-164
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• 2004

Using the data from the KLIPS, this study categorizes unemployed women into the four mutually exclusive groups according to the two criteria (whether to have intention to work and the comparison of reservation and market wages), and investigates factors affecting the status of the unemployment of women. Heckman's sample selection regression and multinomial logit are applied for the estimation. The major results are: the proportion of unemployed women who do not have intension to work or whose reservation wages are greater than expected market wages is about 50%, and the proportion of unemployed women who have intension to work or whose reservation wages are less than expected market wages is about 50%; second, human capital, burden of child raising and household production, household economic status, the variables related to work experience are found to be the factors affecting unemployment status of women.

• IE interfaces
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• v.2 no.2
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• pp.63-73
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• 1989

The present paper determines the equilibrium price function of used goods and their carry-over age when there are heterogeneous firms with different factor prices. It is shown that the used good market enables more efficient use of durable goods and thereby gains from trades. It is also shown that firms with a lower interest rate and a higher wage rate specialize in using newer goods.

• Journal of Labour Economics
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• v.30 no.2
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• pp.33-60
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• 2007

This study analyzes the trend of the gender wage gap and its sources in the Korean labor market for the years 1985-2004. Following Oaxaca and Ransom (1994), the gender wage gap is composed of the productivity-related gap and non-productivity-related gap (unobserved productivity gap and discrimination). Empirical findings indicate that both the productivity-related gap and non-productivity-related gap have dwindled, while the decline of the former far excelled that of the latter. The non-productivity-related gender wage gap is much larger for married women than for single women, possibly implying a lower unobserved productivity of married women because of their childcare responsibilities. The non-productivity-related gap is also very substantial in the male-dominated occupations as compared to the female=dominated occupations, supporting the existence of network externalities in employment.

• Industry Promotion Research
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• v.1 no.1
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• pp.59-64
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• 2016

This study verified the effect of the experience of job-training on youth employees' wage by analyzing panal data. The study results showed that the objective of job-training(enhancing job performance, ${\beta}=.336$), satisfaction of job-training(${\beta}=.-.256$) and the type of job-training(cyber lecture, ${\beta}=.334$) significantly affected youth employees' wage. Also, age, education, marital status, hour of job-training, objective of job-training and satisfaction of job-training significantly affected the differences between groups. This study provided practical implication to prepare effective job-training policy by confirming the effect of the experience of job-training on youth employees' wage and verifying the effectiveness of job-training.

• Korean Journal of Social Welfare
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• v.65 no.2
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• pp.79-102
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• 2013

This study aimed at empirically analysing the double discrimination on the elderly with disabilities due to both age and disabilities in the labor market. To achieve this research goal, real employment probabilities and hourly wages of the elderly disabled(below "ED") were compared with those of the young disabled(below "YD") and those of the elderly non-disabled(below "END") to calculate empirical differentials between ED's and YD's, and ED's and END's. The differential decompositions between groups were applied by the Oaxaca(1973). The study results were as followings. First, the real gaps of the employment probabilities between ED and YD only appeared at the regular jobs and the gaps due to the characteristics between ED and YD were bigger than those due to the age discrimination. Second, on the contrary, the gaps of the hourly wages were caused by age discrimination more than characteristics between YD and ED. Third, it was not true that the elderly with disabilities take double discriminations in the labor market. It is therefore required to give the additional incentives to ED workers with government subsidies of employment promotion for the disabled provided. Second, it is proposed that the integrations the employment policies for the disabled with those for the aged because the disability as dependent valuable didn't have statistically significant effects on the employment probabilities and the hourly wage levels.