Parity disparity: Educational differences in Nordic fertility across parities and number of reproductive partners

Most research on trends in socioeconomic fertility differences focus on cohort total fertility. This study asks how cohort trends in parity-specific fertility differ across educational segments for men and women, and what role multi-partner fertility plays in these trends. The study used Finnish and Swedish register data on cohorts born in 1940–1973/1978. The main analyses use parity progression ratios. Ordinary ratios were contrasted with ratios on births to first reproductive partner. Among low- and medium-educated persons we observe parity polarization, where both childlessness and higher parity (3+) births increase, largely reflecting increases in multi-partner fertility. Highly educated men and women more often have exactly two children. We demonstrate that cohort total fertility can mask significant parity-specific trends across educational groups, and that changes in multi-partner fertility can be a part and parcel of cohort trends in socioeconomic fertility differentials.