This study empirically examines changes in income-based differential fertility and disparities in child-related consumption among households with infants or preschoolers in South Korea, using the Household Income and Expenditure Survey (HIES) from 199...
This study empirically examines changes in income-based differential fertility and disparities in child-related consumption among households with infants or preschoolers in South Korea, using the Household Income and Expenditure Survey (HIES) from 1998 to 2024. Although the financial burden associated with childrearing has long been identified as a major factor behind low fertility, integrated analyses of when, how, and by which socioeconomic groups child-related spending has evolved, and how these spending patterns are structurally connected to fertility decline remain extremely limited.
To address this gap, this study traces long-term shifts in the income-quintile distribution of households with children aged 0–5, and compares trends in the level and composition of child-related expenditures. Methodologically, LOWESS was used to visualize the trend in consumption gaps, Bai–Perron multiple structural break models were applied to identify breakpoints, and natural cubic spline regressions were used to test the statistical significance of changes in inter-quintile consumption disparities.
The analysis reveals that the intensifying concentration of births among high-income groups has occurred alongside statistically significant reorganizations of child-related consumption at specific points in time. The main findings are as follows.
First, the distribution of households with young children shows a sequential collapse across income groups. The decline in fertility began earliest among the lowest-income quintile, which now accounts for the smallest share of all households with children aged 0–5. The second quintile followed a similar path beginning in the mid-2000s, while the third quintile—historically a central contributor to fertility—began to lose ground to the fourth quintile in 2016 and to the fifth quintile in 2020. By contrast, the share of the highest-income quintile increased from 15.9% in 1998 to 37.7% in 2024, becoming the group with the highest proportion of young-child households. These patterns indicate that fertility has become progressively concentrated among economically advantaged households.
Second, child-related spending has risen overall, with non-education expenditures consistently comprising the largest share of total child costs among 0–5-year-old households. In 1998, non-education spending was approximately three times higher than education spending; in 2024, it remained more than double. This reflects the dominance of care-and development-oriented spending over educational expenditures during early childhood.
Third, although high-income households continue to spend the most on children in absolute terms, spending growth rates were substantially higher among low and middle-income groups. From 1998 to 2024, total child-related spending increased by 95.8% in the bottom combined quintile (1st–2nd) and 96.5% in the third quintile, compared to 57.8% and 70.3% in the fourth and fifth quintiles, respectively.
Fourth, structural break and spline analyses show that disparities in non-education spending shares between low to middle-income and high-income households have significantly narrowed in recent years. In contrast, disparities in education spending have widened, driven primarily by sharp increases among the highest-income quintile. This implies a dual burden for lower-income households as they face both upward pressure on non-education outlays and a widening gap in educational investment.
Taken together, these findings indicate that South Korea’s ultra-low fertility emerges not from a uniform decline but from an asymmetric, stratified exit from childbearing across socioeconomic groups. By integrating fertility patterns with long-term shifts in child-related consumption, this study provides an new perspective on the socioeconomic structuring of parenthood in contemporary Korea. The alignment between changes in differential fertility and shifts in consumption disparities at key turning points highlights the dynamic interplay between demographic and economic behaviors. Ultimately, this study offers empirical insights into how structural inequality in childbearing and childrearing has evolved, providing a basis for designing future fertility and family policies.