Ultra-low fertility in South Korea: The role of the tempo effect

City-level population projection for China under different pathways from 2010 to 2100

Cities play a fundamental role in policy decision-making processes, necessitating the availability of city-level population projections to better understand future population dynamics and facilitate research across various domains, including urban planning, shrinking cities, GHG emission projections, GDP projections, disaster risk mitigation, and public health risk assessment. However, the current absence of city-level population projections for China is a significant gap in knowledge. Moreover, aggregating grid-level projections to the city level introduces substantial errors of approximately 30%, leading to discrepancies with actual population trends. The unique circumstances of China, characterized by comprehensive poverty reduction, compulsory education policies, and carbon neutrality goals, render scenarios like SSP4(Shared Socioeconomic Pathways) and SSP5 less applicable. To address the aforementioned limitations, this study made three key enhancements, which significantly refines and augments our previous investigation. Firstly, we refined the model, incorporating granular demographic data at the city level. Secondly, we redesigned the migration module to consider both regional and city-level population attractiveness. Lastly, we explored diverse fertility and migration scenarios.

Probabilistic population forecasting: Short to very long-term

Population forecasts are used by governments and the private sector for planning, with horizons up to about three generations (around 2100) for different purposes. The traditional methods are deterministic using scenarios, but probabilistic forecasts are desired to get an idea of accuracy, assess changes, and make decisions involving risks. In a significant breakthrough, since 2015, the United Nations has issued probabilistic population forecasts for all countries using a Bayesian methodology that we review here. Assessment of the social cost of carbon relies on long-term forecasts of carbon emissions, which in turn depend on even longer-range population and economic forecasts, to 2300. We extend the UN method to very-long range population forecasts by combining the statistical approach with expert review and elicitation. While the world population is projected to grow for the rest of this century, it will likely stabilize in the 22nd century and decline in the 23rd century.

On the Quantum and Tempo of Women First Marriages in China

The total first marriage rate (TFMR) of Chinese women shows a downward trend in fluctuations from 1970 to 2016, but it is affected by the tempo distortion caused by changes in the mean age at first marriage. Thus, we compare the total first marriage rate (TFMR) and tempo-adjusted period proportion ever married (PPEM*) to estimate the extent to which the TFMR is affected by tempo effects. We also decompose the women's TFMR change into its quantum and tempo components from 1970 to 2016 to analyze how much of the changes in TFMR are due to the quantum changes and how much of it is caused by tempo effects. The results show that the tempo effects have had a persistent influence on the period TFMR of Chinese women from 1970 to 2016. The recent decline in the TFMR in Chinese women is mainly due to the first marriage delay, not signaling a retreat from universal marriage.

The Korean Pregnancy Outcome Study (KPOS): Study Design and Participants

BACKGROUND

The Korean Pregnancy Outcome Study (KPOS) was established to investigate the determinants of adverse pregnancy outcomes among Korean women.

METHODS

We recruited 4,537 pregnant women between 2013 and 2017 from two tertiary centers located in Seoul, Korea, and a total of 4,195 Korean women met inclusion criteria in the baseline analysis. A range of data on socio-demographics, past medical histories, reproductive information, health-related behaviors, psychological health and clinical information were obtained using interviewer-based questionnaires and clinical assessment at 12, 24, and 36 gestational weeks (GW), delivery and 6-8 weeks postpartum. Blood samplings were performed at 12, 24 and 36 GW, and placental tissues were obtained after delivery. The main outcome of this study was pregnancy-related complications including gestational diabetes mellitus (GDM), gestational hypertension, and screening positive for peripartum depression. Depression was assessed using the Korean version of the Edinburgh Postnatal Depression Scale, and a score of ≥10 indicated a positive screen for depression.

RESULTS

Among 4,195 eligible pregnant women with a median age of 33.0 years, 3,565 (85.0%) pregnancy outcomes were available in this study, including 30 miscarriages, 16 stillbirths, and 3,519 deliveries. Mean gestational age was 38.8 GW, and mean birth weight was 3,236 gram. The prevalence of pregnancy complications of GDM, hypertensive disorders, and screening positive of depression during pregnancy and postpartum was 7.0%, 1.4%, 27.8%, and 16.6%, respectively.

CONCLUSIONS

We designed KPOS to identify the determinants of pregnancy-related outcomes, and it may provide effective strategies for the prevention of pregnancy complications in Korean pregnant women.

Marriage Decline in Korea: Changing Composition of the Domestic Marriage Market and Growth in International Marriage

Explanations for the substantial decline in rates of marriage in East Asian countries often emphasize the role of rapid educational expansion for women in reducing the desirability of marriages characterized by a strong gender-based division of labor. Focusing on South Korea, we consider a very different scenario in which changing educational composition of the marriage market reduces the demographic feasibility of such marriages. Analyses of 1% microsamples of the 1990 and 2010 Korean censuses show that changes in the availability of potential spouses accounted for part of the decline in marriage rates over a period of 20 years (1985-1989 to 2005-2009) for highly educated women and less-educated men. We also show that growth in international marriages played a role in preventing an even more dramatic decline in marriage among low-educated men. These findings support the general relevance of marriage market mismatches in gender-inegalitarian societies and highlight the declining feasibility of marriage for low-educated men in such contexts. Findings also hint at important implications for inequality in a society such as Korea, where marriage remains a symbol of social success and is closely related to women's economic well-being and men's health and subjective well-being.

An Investigation into Chronic Conditions and Diseases in Minors to Determine the Socioeconomic Status, Medical Use and Expenditure According to Data from the Korea Health Panel, 2015

Objectives

This study compared the socioeconomic status, medical use and expenditures for infants (1–5 years), juveniles (6–12 years), and adolescents (13–19 years) with a chronic condition or disease to determine factors affecting health spending.

Methods

Data from 3,677 minors (< 20 years old, without disabilities) were extracted from the Korea Health Panel (2015) database.

Results

Minors with chronic conditions or diseases were older (juveniles, and adolescents; p < 0.001), and included a higher proportion of Medicaid recipients (p = 0.004), a higher use of hospital outpatient care (p < 0.001), and higher medical expenditure (p < 0.001) compared to minors without chronic conditions or diseases. Boys were more likely to have a chronic condition or disease than girls (p = 0.036). Adolescents and juveniles were more likely than infants to have a chronic condition or disease (p = 0.001). Medicaid recipients were more likely to have a chronic condition or disease than those who were not Medicaid recipients (p = 0.008). Minors who had been hospital outpatients were more likely to have a chronic condition or disease, compared with minors who had not been an outpatient (p = 0.001). Having a chronic condition or disease, was a factor increasing medical expenditure (p = 0.001). Medical expenditure was higher in infants than in juveniles and adolescents (p = 0.001). Infants had higher rates of medical use when compared with juveniles and adolescents (p = 0.001).

Conclusion

These findings suggest that systematic health care management for minors with chronic conditions or diseases, is needed.

Association between irregular menstrual cycles and occupational characteristics among female workers in Korea

OBJECTIVE

To examine the association between irregular menstrual cycles and occupational characteristics among Korean female workers.

STUDY DESIGN

We analyzed data on paid female workers from the Korea National Health and Nutrition Examination Survey (KNHANES) V (2010-2012).

MAIN OUTCOME MEASURES

We evaluated the possible associations between irregular menstrual cycles and work variables (occupational classification, working hours, and shift work) using univariate and multivariate logistic regression analyses. Weighted prevalence was calculated according to each work variable to approximate the Korean population.

RESULTS

Irregular menstrual cycles were the most common in women in the 'pink collar' group (16.61%). The frequency of irregular menstrual cycles was 2-fold higher in women working >60 h per week (25.64%) than in those working 20-60 h per week (11.09%). Irregular menstrual cycles were more prevalent in shift workers (15.85%) than in non-shift workers (11.06%). A significantly high risk of irregular menstrual cycles was found for pink-collar occupations (adjusted odds ratio [OR] = 1.687, 95% confidence interval [CI] = 1.044-2.710, reference: white-collar occupation group) and in women with long working hours (adjusted OR = 2.139, 95% CI = 1.243-3.559, reference: 20-60 working hours group) and shift work (adjusted OR = 1.487, 95% CI = 1.028-2.118, reference: fixed working schedule group).

CONCLUSIONS

Our study showed associations between irregular menstrual cycles and occupational characteristics of female workers. Long working hours, shift work, and pink-collar occupations are positively associated with irregular menstrual cycles. Therefore, working hours and shift schedules for female workers should be structured considering these factors. Further research is needed to determine the optimal working time and shift schedules for female workers.

Gender Discrimination in the Workplace: Effects on Pregnancy Planning and Childbirth among South Korean Women

Introduction: This study aims to investigate the association between gender discrimination in the workplace and pregnancy planning/childbirth experiences among working women in South Korea. Methods: We analyzed data from the Korean Longitudinal Survey of Women and Families (KLoWF) for the years 2007 to 2016. The study population consisted of 7996 working women, between the ages of 19 and 45. Gender discrimination was measured through the 6-item Workplace Gender Discrimination Scale, evaluating discrimination in terms of recruitment, promotions, pay, deployment, training and lay-offs. Multiple logistic regression analysis was employed to measure the association between gender discrimination and the pregnancy planning/childbirth experience. Results: Compared to individuals experiencing no discrimination in the workplace, those experiencing low [odds ratio (OR): 0.78, 95% confidence interval (95% CI) 0.61-0.99] or medium (OR: 0.69, 95% CI: 0.54-0.89) levels of discrimination had decreased odds of pregnancy planning. Likewise, individuals scoring low (OR: 0.70, 95% CI 0.54-0.92), medium (OR: 0.68, 95% CI: 0.51-0.92), or high (OR: 0.47, 95% CI: 0.27-0.80) levels of discrimination also had decreased odds of childbirth experience when compared to the no-experience group. When stratified by income, compared to individuals experiencing no discrimination in the workplace, those experiencing gender discrimination had decreased odds of pregnancy planning for low income (low OR: 0.64, 95% CI: 0.45-0.92; medium OR: 0.55, 95% CI: 0.52-0.97; high OR: 0.45, 95% CI: 0.24-0.87), medium income (medium OR: 0.53, 95% CI: 0.37-0.77; high OR: 0.29, 95% CI: 0.14-0.63), and high income groups (low OR: 0.64, 95% CI: 0.49-0.84; medium OR: 0.69, 95% CI: 0.52-0.92). Conclusions: The present study finds that gender discrimination in the workplace is associated with decreased odds of pregnancy planning/childbirth experience among working South Korean women. Furthermore, low and medium income groups were especially more likely to be affected by the level of gender discrimination in the workplace when planning pregnancy.