Partnership dynamics and the fertility gap between Sweden and Spain

Abstract

AbstractBelow-replacement fertility has persisted across European countries for a few decades, though, with variation. Delays in age at first union and first birth have been key factors in the declining fertility levels within these societies. While the vast majority of births occurs within a stable partnership, the link between partnership formation and childbearing is rarely taken into account. In this paper, we examine the role of partnership formation in explaining the gap between Sweden and Spain regarding transitions to first birth. We utilize data from the 2018 Spanish Fertility Survey and the 2012/2013 Swedish Generations and Gender Survey to explore transition probabilities to first birth and implement Kitagawa decomposition and standardization techniques. Results show that having a partner is a strong predictor of becoming a first-time parent in the next 3 years, mainly within the ages 25 to 35. On average, Swedish first-birth transition probabilities for women are only 12% higher than probabilities of Spanish counterparts within this age range, suggesting that the proportion of partnerships formed plays a crucial role in explaining the fertility gap. Decomposition results confirm that before age 30, 74% of the difference in first-order births among women are due to the difference in partnership composition. We further find that earlier union formation in Spain could potentially reduce childlessness levels. Overall, our study highlights the importance of examining the role of partnership dynamics in fertility studies.