• Journal of the Korean Data and Information Science Society
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• v.28 no.5
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• pp.1077-1085
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• 2017

In this study, we have found the major factors which affect Korean women's wage analysing the data provided by 2015 Korea Labor Panel Survey (KLIPS). In general, wage data is difficult to analyze because random sampling is infeasible. Heckman sample selection model is the most widely used method for analysing the data with sample selection. Heckman proposed two kinds of selection models: the one is the model with maximum likelihood method and the other is the Heckman two stage model. Heckman two stage model is known to be robust to the normal assumption of bivariate error terms. Recently, Marchenko and Genton (2012) proposed the Heckman selectiont model which generalizes the Heckman two stage model and concluded that Heckman selection-t model is more robust to the error assumptions. Employing the two models, we carried out the analysis of the data and we compared those results.

• Journal of the Korean Regional Science Association
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• v.40 no.3
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• pp.43-61
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• 2024

The purpose of this study is to identify the difference of regional characteristics affecting 'marriage stage' and 'childbirth stage' and to compare how these factors differ between metropolitan and non-metropolitan areas using a heckman two-stage selection model. The main findings are as follows. First, regional characteristics affecting marriage stage and childbirth stage are different. Second, in the metropolitan area, regional characteristics such as population density, the proportion of female employee, and housing prices have a relatively greater impact on 'marriage', and in the non-metropolitan area, regional characteristics such as population density and unemployment rate have more impact on 'childbirth'. The empirical analysis suggests that marriage and childbirth stage need to be distinguished when establishing low fertility policies, and these approaches should be differentiated at regional level.

• The Korean Journal of Applied Statistics
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• v.31 no.6
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• pp.733-749
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• 2018

Sample selection arises as a result of the partial observability of the outcome of interest in a study. Heckman introduced a sample selection model to analyze such data and proposed a full maximum likelihood estimation method under the assumption of normality. Recently sample selection models for binomial and Poisson response variables have been proposed. Based on the theory of symmetry-modulated distribution, we extend these to a model for overdispersed count data. This type of data with no sample selection is often modeled using negative binomial distribution. Hence we propose a sample selection model for overdispersed count data using the negative binomial distribution. A real data application is employed. Simulation studies reveal that our estimation method based on profile log-likelihood is stable.

• 한국사회정책
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• v.24 no.1
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• pp.1-31
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• 2017

This paper attempts to analyze citizens' giving behavior by household income level. Particularly, it focuses on participation and amount of secular giving by using 'Social Survey'in 2011, 2013, and 2015 from the Bureau of Statistics and employing Heckman selection model for statistical analysis. This study shows that citizens' participation has a proportional tendency by their income level. Similar to participation of secular giving, citizens' giving amount has also a proportional tendency by their income level. However, the degree of proportional tendency seems not to be significant in the case of amount of secular giving. This empirical analysis promotes understanding of participation and amount of secular giving by citizens' income section in Korea by showing the differences. This paper provides meaningful empirical understanding regarding citizens' secular giving behavior by their income level. In addition, it offers important clues to motivate relevant prospective studies and develop social agenda which contribute to strengthening giving culture in Korea.

• Korean Journal of Construction Engineering and Management
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• v.20 no.6
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• pp.57-65
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• 2019

If aging apartments are left unimproved through remodeling, the city will be eventually slum. As the government recognizes remodeling as an alternative to reconstruction, the law has been revised mainly to increase the housing area, increase the number of house and allow the vertical extension for making remodeling costs. However, the remodeling is still not activated yet in the market. Therefore, this study analyzes the decision factors of apartment remodeling in Seoul metropolitan area based on Heckman two-stage analysis considering sampling error. Research findings indicate that the decision for remodeling is determined by the characteristics of the household, housing, and time-lapse variables. And also the number of household members, net assets, housing satisfaction, the 11-20, 21-30, and more than 30 years of building are identified as the significant variables as a result of remodeling choice probability analysis. It is noteworthy that the significant variables from then remodeling cost analysis are net assets, area, more than 30 years of building, and unit housing price. It is also notable that the policy, which extend the housing area to cover remodeling cost, are not actually effective to activate the remodeling, and the age in the case of elderly people in Seoul and Gyeonggi-do who are expected to have high net assets and income is not significant variables. This study is expected to provide more objective and reliable implication to the policy makers, the home owner and the investors on the decision making process related to the remodeling project.

• Korean Journal of Social Welfare Studies
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• v.43 no.2
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• pp.345-366
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• 2012

This study analyze Family gaps(the wage gap between mothers and non-mothers) across the wages distribution in Korea using 2008 Korean Labor and Income Panel Study. Analysis models include Heckman's two stage estimation to control women's labor participation selection and Quantile regression method to examine the effects of children at different points of the wage distribution. The result indicates that first, comparing non-mothers, mothers with one child suffer statistically significant hourly wage losses at 25th, 50th, and 75th distribution, however not significant effects are found at lowest(10th) and highest(90th) distribution. Second, comparing non-mothers, mothers with two more children suffer statistically significant hourly wage losses at all distribution. Family gap differs across the wage distribution and highest family gaps are found at 25th distribution. With these results, the author suggests universal family policies to support mothers' labor participation and the reconciliation of work and family.

• Informatization Policy
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• v.30 no.2
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• pp.22-45
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• 2023

In research on the use of AI-based voice assistant services, problems related to the user's trust and privacy protection arising from the experience of service use are constantly being raised. The purpose of this study was to investigate empirically the effects of individual trust in AI and online privacy concerns on the continued use of AI-based voice assistants, specifically the impact of their interaction. In this study, question items were constructed based on previous studies, with an online survey conducted among 405 respondents. The effect of the user's trust in AI and privacy concerns on the adoption and continuous use intention of AI-based voice assistant services was analyzed using the Heckman selection model. As the main findings of the study, first, AI-based voice assistant service usage behavior was positively influenced by factors that promote technology acceptance, such as perceived usefulness, perceived ease of use, and social influence. Second, trust in AI had no statistically significant effect on AI-based voice assistant service usage behavior but had a positive effect on continuous use intention. Third, the privacy concern level was confirmed to have the effect of suppressing continuous use intention through interaction with trust in AI. These research results suggest the need to strengthen user experience through user opinion collection and action to improve trust in technology and alleviate users' concerns about privacy as governance for realizing digital government. When introducing artificial intelligence-based policy services, it is necessary to disclose transparently the scope of application of artificial intelligence technology through a public deliberation process, and the development of a system that can track and evaluate privacy issues ex-post and an algorithm that considers privacy protection is required.