Is Two Still Best? Change in Parity-Specific Fertility Across Education in Low-Fertility Countries

Abstract

The dominance of two-child families is considered an intrinsic characteristic of low fertility societies. Their share was continuously increasing among baby boom cohorts but the rise ceased afterwards. While parity- and education-specific fertility trends during the expansion of the two-child families have been studied, corresponding analyses of developments in the post-expansion birth cohorts are scarce. This study investigates the parity-specific fertility trends that ended the expansion of two-child families across educational groups. We use data on completed fertility of female cohorts born between 1936 and 1970 in 16 low-fertility countries. Besides examining trends in education- and parity-specific fertility, we provide evidence on increasing variation in family size and on the contribution of parity-specific fertility to the share of two child families among women with low, medium and high education. Our results show that the expansion of two-child families stopped as the variation in family size increased: transition rates to first and/or second birth declined whereas those to third birth increased. This polarisation process was strongest among women with low education. Apparently, as the number of women progressing to second birth declined, they became more selected and family-oriented, and thus more likely to progress to further births. The fact that the strongest polarisation of fertility was observed among the low educated reflects the group’s increasing selectivity. We demonstrate that rising polarisation of family size is a common development to most high-income low-fertility populations, especially among the low educated, regardless of substantial cross-country differences in fertility levels as well as in institutional, economic and cultural settings.