Analysis of Factors Influencing the First Birth Interval in the Gyeonggi Province, South Korea

Abstract

Objectives: The main purpose of this study was to identify and examine associative factors that affect the first birth interval, the duration between marriage and first birth in the 31 cities and counties of Gyeonggi, the most populous province in Korea. In addition to individual characteristics of parents, focus was also on regional characteristics in order to explore what factors in a certain living environment hasten or postpone a couples entry into parenthood. The paper covers the period 2008-2014.

Methods: This study used the complete birth certificate data for 2008-2014 provided by the Microdata Integrated Service (MDIS) of Statistics Korea and the regional time-series data for the same time period, collected through the Korean Statistical Information Service (KOSIS). Response variable was the first birth interval, defined as the difference between the marriage year and month and the first childs birth year and month. Explanatory variables from the micro dataset were socio-demographic characteristics of parents, which consisted of age at marriage, age difference, education level, occupation and labor force participation status. The macro dataset consisted of explanatory variables categorized by demographic, housing, economic and child care policy-related variables. A multilevel multinomial logistic regression was conducted using SAS 9.4.

Results: A multinomial logistic regression was conducted to analyze individual characteristics of couples who gave their first birth 1 to 5 or more years following their marriage compared to those who gave birth within the first year of marriage. Based on the univariate analysis, statistically significant variables at the individual level were education level, fathers occupation and mothers labor force participation status

age at marriage, especially paternal age, and age difference between parents were not as significant as the other factors. There was a common tendency among college graduate parents to give birth at a later time compared to their high school graduate counterparts. College graduate parents also showed a low tendency to give first birth within the first year of marriage. Lastly, there was a higher proportion of childbirths occurring progressively later after marriage among the employed in contrast to the unemployed. Results from the multivariate analysis were generally similar to those of univariate analysis. In the multivariate analysis of the aggregate data, most of the variables from each category were statistically significant. The findings were as follows: proportion of women with high education, female employment rate, unemployment rate, housing prices were positively associated with the first birth interval whereas employment rate, GRDP, financial independence and the number of childcare facilities per child mainly showed negative relationships with the first birth interval.

Conclusions: This study aimed to examine primarily demographic and socioeconomic factors that influence the length of time between marriage and first birth in the Gyeonggi province, South Korea both at the individual and aggregate level from 2008 to 2014. Through statistical analyses the general pattern indicated that the majority of the individual and regional variables were significantly affecting the first birth interval. It is highly likely that the findings of this study will serve as a reference for prospective research concerning first birth intervals and also contribute to the implementation of more effective low fertility and policy response at the provincial level in Korea.