Estimating fertility rates using the ONS Longitudinal Study ‐ what difference does the inclusion of non‐continually resident members make?

Abstract

Among datasets available for fertility research in England and Wales, the Office for National Statistics (ONS) Longitudinal Study (LS) is unique in its construction and scale. The large number of individuals who are part of the study means that it is an important dataset for estimating fertility trends in England and Wales by age and parity. This article uses the LS to estimate age-specific fertility rates (ASFRs) for England and Wales between 1991 and 2001. This necessitates great care to ensure that the exposure to risk of birth for female LS members is fully understood. To achieve this, two forms of residential history are definedconsistent cases where the residential information for the LS member is potentially complete for the whole decade and inconsistent cases where there is certainly some form of incompleteness in the residence information. By considering 'all consistent cases', that is both the continuously resident plus those who are not continuously resident but appear to have a complete residential history, we obtain ASFRs which are slightly lower than official statistics figures, but closer to these official figures than ASFRs produced when restricting the sample to LS members who remain continuously resident between 1991 and 2001. The fertility of those consistent cases who are not continuously resident is substantially higher than the rates of continuously resident cases.

Age at first birth and subsequent fertility: The case of adolescent mothers in France and England and Wales

“…Nevertheless, the level of fertility calculated using the EDP is slightly underestimated (Robert-Bobée 2006). A slight underestimation of the quantum of fertility also exists in the LS (Robards, Berrington, and Hinde 2011).…”

Residential segregation and the fertility of immigrants and their descendants

“…The LS contains register data on vital events, including births registered in England and Wales since 1971. The accuracy of the LS data has been investigated, both in general (Blackwell, Lynch, Smith, & Goldblatt, ; Hattersley & Creeser, ) and with respect to migration and fertility (Hattersley, ; Robards, Berrington, & Hinde, , ; Wilson, ). Although the quality of the data is very good, the immigration and emigration of LS members is sometimes not recorded (Robards et al, ).…”

Visualising Immigrant Fertility -- Profiles of Childbearing and their Implications for Migration Research

“…Furthermore, even in contexts where data limitations make it difficult to plot fertility profiles, we hope that the visualisations presented here can illuminate some of the challenges of measuring immigrant fertility, raise awareness of each measure's strengths and weaknesses, and guide researchers when choosing the most relevant approach for their study. (Coleman 1994;Dormon 2014;Fokkema et al 2008;Héran and Pison 2007;Iliffe 1978;Robards et al 2011;Toulemon 2004;Tromans et al 2007;Van Landschoot et al 2014;Zumpe et al 2012) Adjusted TFR comparison a Survey or administrative data (Kulu et al 2019;Persson and Hoem 2014;Toulemon 2006) Measures based on event history approaches Survey or administrative data on birth histories (Andersson 2004;González-Ferrer et al 2017;Jensen and Ahlburg 2004;Kulu 2005;Giorguli Saucedo 2002, 2007;Milewski 2010b;Mussino et al 2010;Puur et al 2017;White et al 1995;Wolf 2016) Measures of number of children ever born…”