Understanding How Immigrant Fertility Differentials Vary over the Reproductive Life Course.

Studies of immigrant fertility differentials indicate that foreign-born women have more children than native-born women, at least for some origin groups. Yet little is known about variation in cumulative fertility differentials over the life course, including the extent to which this variation develops into completed fertility differentials. This research responds with an analysis of cumulative fertility differentials in the UK for a cohort of women born between 1942 and 1971. Findings are consistent with age-specific patterns that have been documented for immigrant groups in the UK, but underline the importance of taking a cohort perspective, which helps to distinguish between the tempo and quantum of fertility. Immigrants have significantly higher completed fertility than UK-born natives if they were born in India, Pakistan, Bangladesh, Jamaica, or Western and Central Africa, but the profile of their cumulative fertility differentials-versus the UK-born-varies considerably over the life course, especially by age at migration. For example, women from Bangladesh and Pakistan have similar levels of cumulative fertility at age 40, but very different age patterns of cumulative fertility from ages 20-40. There is a consistent pattern of relatively delayed Pakistani fertility at early ages, especially for those arriving at later ages, but the same is not true for women from Bangladesh. Overall, these results imply that researchers should beware of variation in cohort fertility over the life course-with respect to both the quantum and tempo of fertility-when analysing immigrant childbearing, in addition to variation by origin and age at arrival.