Disentangling the quantum and tempo of immigrant fertility

Migrant fertility has become an increasingly prominent explanation for recent fertility change. Immigrant Total Fertility Rates (TFRs) are consistently higher than native TFRs in the majority of European countries. However, research has cast doubt on the use of tempo-distorted measures of fertility for evaluating the contribution of immigrants to aggregate fertility. Furthermore, previous research has almost exclusively analysed incomplete fertility profiles, an approach which provides little insight into the absolute impact of immigrant fertility.

Considering the UK, this research uses survey estimation and count regression techniques to disentangle tempo variation from the quantum of immigrant fertility. This approach is crucial for testing migrant fertility hypotheses because migration is known to influence the timing of childbearing. The results support several hypotheses, with evidence of disruption followed by elevated fertility, particularly for recent cohorts of women arriving after age 25. This may be explained by selection, anticipation, or adaptation. However, the results show no evidence of disruption for immigrants from Jamaica or Bangladesh, suggesting cultural maintenance or socialisation for these groups. The paper concludes with an appraisal of the method used here, and its benefits for future research.