Understanding the sex inequality in childlessness: an approach using Swedish register data

In most countries, men are more likely to be childless than women. Understanding how this inequality arises is important given the significance of parenthood for individuals' lives. The objective of this study was to explore how three prominent explanations for sex inequalities in childlessness relate to the Sex Gap in Childlessness (SGC) in Sweden. The three explanations examined were sex ratio imbalance (more men than women), mismeasurement of fatherhood (inequalities in registration) and partnership differences (inequality in multi-partner fertility). Administrative register data for cohorts born in 1945-1974 were used. The population was restricted to men and women who were born in Sweden or arrived prior to the age of 15, and all registered childbearing partnerships were examined. To explore the possible significance of the three explanations, counter-factual standardization was used. Of the three explanations examined, the population sex ratio had the largest positive impact on the SGC, while multi-partner fertility had a negative impact. The results show that inequalities in the sex ratio can explain about 20-34% of the SGC depending on cohort. Inequalities in registration of fathers explain about 9-24% of the SGC depending on cohort. Finally, results show that women are slightly more likely to have multiple partners, and that this behaviour has a substantial minimizing effect on the SGC (minimizing it by 6-65%). To the authors' knowledge this was the first paper to estimate the scope of the impacts of these three mechanisms on the SGC. Differences in multi-partner fertility have in many instances been used as an explanation for men's higher childlessness. This study shows that women have slightly more childbearing partners than men, and that this actually leads to a smaller SGC in the studied population.