Lifetime parenthood in the context of single- and multiple-partner fertility

Educational Gradient of Multi-partner Fertility: First Estimates for the UK

Recent demographic changes in Western countries have resulted in higher rates of partnership dissolution and serial partnering, and an increase in childbearing across multiple partnerships. This has given rise to more complex family dynamics including multi-partner fertility (MPF), defined as having biological children with two or more partners. Yet estimates of MPF in the UK have not previously been available. This paper describes an 'indirect approach' to estimate the prevalence of MPF in the UK, for men and women, given different assumptions. The paper additionally explores differences in MPF according to own and parental educational attainment. Amongst those born in Britain in 1970, 12-14% of men and 15-18% of women experienced MPF by age 42, depending on the assumptions made. For most of the cohort, MPF occurred with two different coresidential partners. We have established that MPF is a common family formation in the UK, but there are large educational disparities in MPF prevalence.

Kinship and socio-economic status: Social gradients in frequencies of kin across the life course in Sweden

The influence of kin on various outcomes is heavily debated. However, kinship size itself conditions the probability of potential effects. Socio-economic gradients in the prevalence, variance, and types of kin are, therefore, a vital aspect of the functions of kin. Unfortunately, these parameters are largely unknown. We used Swedish register data to enumerate consanguine and in-law kin across the life course of the 1975 birth cohort. We calculated differences in kinship size between this cohort's income quartiles and educational groups. We decomposed how specific kin relations, generations, and demographic behaviours contributed to these differences. Among low socio-economic status (SES) groups, higher fertility in earlier generations resulted in more kin compared with high-SES groups. Low-SES groups had more horizontal consanguine kin, while high-SES groups had more in-laws. Lower fertility and higher union instability among low-SES men substantially narrowed SES differences in kinship size. Kinship size varied substantially within SES groups.

The Role of Gender Differences in Partnering and Re-partnering for Gender Differences in Completed Fertility

Individuals increasingly enter a series of relationships during their reproductive years. As births in higher-order unions increase, fertility becomes partially contingent on re-partnering. Previous research suggests that men re-partner at higher rates than women. This study analyzes whether gender differences in partnering and re-partnering influence gender differences in cohort fertility. We use Finnish register data on all births, marriages, and cohabitations between the ages of 18 and 47 over four full birth cohorts. The gender differences in cohort fertility rate are decomposed into components due to birth rate differences and a compositional component owing to gender differences in the share partnered and re-partnered. We observe no impact of “re-partnering premium” on male fertility. Men have marginally higher re-partnering rates at older ages, when birth rates are low, whereas women have higher rates of partnering and re-partnering at prime childbearing ages. This compositional effect drives a “partnering” advantage for female fertility. This connection between gender differences in partnering and cohort fertility is true across educational levels.

Less Is More? Repartnering and Completed Cohort Fertility in Finland

An extensive literature theorizes the role of repartnering for cohort fertility and whether union dissolution can be an engine for fertility. A large share of higher order unions are nonmarital cohabitations, but most previous studies on completed cohort fertility have analyzed only marital unions, and none have incorporated nonmarital cohabitations using population-level data. To analyze the relationship between the number of unions and cohort fertility for men and women, we use Poisson regression with Finnish register data to enumerate every birth, marriage, and cohabitation among the 1969-1972 birth cohorts at ages 18-46. We show that dissolutions of first cohabitations are the main pathway to repartnering and that most higher order unions are cohabitations. Nonmarital repartnering is a strong predictor of low fertility. In contrast, remarriage is positively associated with cohort fertility. Because the bulk of first-union dissolutions and higher order unions are nonmarital, repartnering is not an efficient engine for fertility at the aggregate level. Marriage and cohabitation are far from indistinguishable in a country often described as a second demographic transition forerunner.