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.