Old Habits Die Hard? Lingering Son Preference in an Era of Normalizing Sex Ratios at Birth in South Korea

South Korea was among the first countries to report both an abnormally high sex ratio at birth (SRB) and its subsequent normalization. We examine the role of son preference in driving fertility intentions during a period of declining SRB and consider the contribution of individual characteristics and broader social context to explaining changes in intentions. We employ data from the National Survey on Fertility, Family Health and Welfare that span 1991–2012. We find that reported son preference declined to a great extent but remained substantial by the end of the observation period, and that the intention to have a third child still differed by sex of existing children. Change in individual-level factors does not explain the decline in son preference, suggesting that broad social changes were also important. This study provides a better understanding of how son preference evolves in the post-transitional context of very low fertility.     

Factors influencing resubstantiation of child neglect in South Korea: A comparison with other maltreatment cases

While a high prevalence of child neglect cases has been reported by Child Protective Services (CPS) in Western countries, child neglect cases reported to South Korea's Child Protection Agency (CPA) present different trends than those in Western countries. Nevertheless, child neglect is an understudied area within child welfare. Thus, a need exists to investigate the unique characteristics of child neglect cases substantiated by the CPA in Korea. This study investigates the unique characteristics of child neglect cases and examines how factors associated with the resubstantiation of these cases differ from those of other maltreatment cases. Using CPA administrative data, we employed a multilevel discrete‐time hazard analysis to analyze the risk and protective factors associated with the resubstantiation of child neglect cases and compared the results with other maltreatment cases. In both cases, younger children, perpetrators with alcohol problems, families receiving welfare, and months of agency operation were associated with resubstantiation. For child neglect cases, the provision of child and parent services, and CPAs located in metropolitan area were protective factors that reduced the risk of resubstantiation. The finding in this study highlights the need to expand the provision of services to child neglect cases to prevent resubstantiation.     

Korean Children's Evaluation of Parental Restrictions Regarding Gender‐stereotypic Peer Activities

Korean children's evaluations of parental restrictions of children's activities based on gender stereotypic expectations were investigated. Third and sixth grade Korean (N = 128) children evaluated scenarios in which a boy or girl desired to play ballet or soccer. Participants used stereotypes to support children's desires to play gender‐consistent activities and adhered to parental authority for choice of gender‐consistent social activities. Yet, they also rejected parental decisions to treat sons and daughters differently based on the view that it would be unfair. Stereotypic expectations decreased with age and were used more by boys than by girls when evaluating exclusion. The results are discussed in terms of exclusion, development, and culture.     

Exploring an analytic model of urban housing strata

An analytic model of urban housing strata is developed which utilizes housing structure type, housing tenure type, floor size, physical quality, residential area, and number of rooms to calculate a housing deficit for each housing characteristic. The housing norm is subtracted from the actual housing conditions. Each housing deficit value is weighted according to the priority of the 6 variables and then summed as the housing strata score. Negative scores are below the norm and positive ones above. The model is applied to empirical data for Seoul, Korea. The findings were that 66% of the family sample showed negative scores (unsatisfactory housing conditions). Scores range from -22 to =or+ 18. Morris and Winter's "housing adjustment model" is used to explain housing behavior when there is a gap between housing conditions and the norm. Housing behavior is analyzed with multiple regression analysis of housing strata, social strata, and family life stage variables. Findings indicate that the establishment stage in the family life cycle is more likely to be associated with upper housing strata. From the way the model is set up only those in the establishment, childbearing, and child-rearing stage could get a positive deficit housing score. Size of household is not statistically significant, but upper housing strata are reflective of families with 2.5 members. Those with 3-4.5 members may be in the upper middle housing strata. Those with 5 children are in the lower middle housing strata. Housing strata are significantly related to housing structure type, tenure type, and size and number of rooms. The high rise apartment is likely to be in the upper, the row house and multifamily house in the lower housing, and the single detached house is distributed through all 4 strata. Home ownership is highest in the upper strata. The proportion of housing with 18 pyong and 2 rooms is higher in the lower strata, while housing with 19-32 pyong (63-106 sq. ms) and 3 rooms is higher in the middle housing strata. Housing satisfaction is significantly explained by housing strata but not general social strata (r = .13). Propensity to move is explained by family life stage followed by housing strata.     

Evaluation of the treatment time-lag effect for survival data

Medical treatments often take a period of time to reveal their impact on subjects, which is the so-called time-lag effect in the literature. In the survival data analysis literature, most existing methods compare two treatments in the entire study period. In cases when there is a substantial time-lag effect, these methods would not be effective in detecting the difference between the two treatments, because the similarity between the treatments during the time-lag period would diminish their effectiveness. In this paper, we develop a novel modeling approach for estimating the time-lag period and for comparing the two treatments properly after the time-lag effect is accommodated. Theoretical arguments and numerical examples show that it is effective in practice.     

Model-Averaged Benchmark Concentration Estimates for Continuous Response Data Arising from Epidemiological Studies

Worker populations often provide data on adverse responses associated with exposure to potential hazards. The relationship between hazard exposure levels and adverse response can be modeled and then inverted to estimate the exposure associated with some specified response level. One concern is that this endpoint may be sensitive to the concentration metric and other variables included in the model. Further, it may be that the models yielding different risk endpoints are all providing relatively similar fits. We focus on evaluating the impact of exposure on a continuous response by constructing a model-averaged benchmark concentration from a weighted average of model-specific benchmark concentrations. A method for combining the estimates based on different models is applied to lung function in a cohort of miners exposed to coal dust. In this analysis, we see that a small number of the thousands of models considered survive a filtering criterion for use in averaging. Even after filtering, the models considered yield benchmark concentrations that differ by a factor of 2 to 9 depending on the concentration metric and covariates. The model-average BMC captures this uncertainty, and provides a useful strategy for addressing model uncertainty.     

Relative error prediction via kernel regression smoothers

In this article, we introduce and study local constant and local linear nonparametric regression estimators when it is appropriate to assess performance in terms of mean squared relative error of prediction. We give asymptotic results for both boundary and non-boundary cases. These are special cases of more general asymptotic results that we provide concerning the estimation of the ratio of conditional expectations of two functions of the response variable. We also provide a good bandwidth selection method for the estimators. Examples of application, limited simulation results and discussion of related problems and approaches are also given.