Identifying biases arising from combining census and administrative data – the fertility of migrants in the Office for National Statistics Longitudinal Study

Authors

  • James Robards Division of Social Statistics and Demography, School of Social Sciences, University of Southampton ESRC Centre for Population Change, School of Social Sciences, University of Southampton
  • Ann Berrington Division of Social Statistics and Demography, School of Social Sciences, University of Southampton ESRC Centre for Population Change, School of Social Sciences, University of Southampton Southampton Statistical Sciences Research Institute, University of Southampton
  • Andrew Hinde Division of Social Statistics and Demography, School of Social Sciences, University of Southampton Southampton Statistical Sciences Research Institute, University of Southampton

DOI:

https://doi.org/10.14301/llcs.v4i3.244

Keywords:

Office for National Statistics Longitudinal Study, migration, National Health Service Central Register, fertility, longitudinal data

Abstract

Demographic research is increasingly making use of longitudinal and life history data, given its strong analytical potential. Such data are frequently produced by linking and matching records from multiple sources. Where this is the case, there is the potential for a person’s appearance in one source of data to be conditional on an event in another source of data. This can lead to bias in estimating occurrence/exposure rates concerning the event in question, unless the correct exposure can be identified. Achieving the latter requires understanding the reasons governing entry to the data. The Office for National Statistics (ONS) Longitudinal Study (LS) for England and Wales is a 1% sample of the population, constructed by combining data from the census, vital registrations (births and deaths) and the National Health Service Central Register (NHSCR). This paper examines the difficulties in obtaining the correct exposure for rates in complex data sets by studying the fertility of migrants using the ONS LS. Three tests in relation to the fertility of female migrants to England and Wales illustrate the possible association between exposure to risk and subsequent events. The first identifies the ability of the data set to record new migrants, the second is concerned with the mode of entry to the data set and subsequent fertility, and the third illustrates how the recorded fertility of migrants depends upon the way migration is measured.

Author Biographies

James Robards, Division of Social Statistics and Demography, School of Social Sciences, University of Southampton ESRC Centre for Population Change, School of Social Sciences, University of Southampton

Research Fellow

Ann Berrington, Division of Social Statistics and Demography, School of Social Sciences, University of Southampton ESRC Centre for Population Change, School of Social Sciences, University of Southampton Southampton Statistical Sciences Research Institute, University of Southampton

Reader

Andrew Hinde, Division of Social Statistics and Demography, School of Social Sciences, University of Southampton Southampton Statistical Sciences Research Institute, University of Southampton

Senior Lecturer in Demography

Downloads

Published

2013-07-10

Issue

Vol. 4 No. 3 (2013): Longitudinal and Life Course Studies

Section

Papers

License

Authors who published with Longitudinal and Life Course Studies Volumes 1–9 agreed to the following terms:

1. Authors retain copyright and grant the Journal right of first publication with the work, simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.

2. Following first publication in this Journal, Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal, provided always that no charge is made for its use.

3. Authors are permitted and encouraged to post their work online (e.g. in institutional repositories or on their own website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work.