Possible Futures for The ONS Longitudinal Study in a Post-Census Landscape

Nicola Shelton , UCL
Oliver Duke-Williams, UCL University College London

The ONS Longitudinal Study ('the ONS LS', or simply, 'the LS') is an approximately 1% sample of the population of England and Wales, and includes data from all censuses from 1971 onwards (for as many censuses as sample members were alive, present (and in the census) in England and Wales, and successfully linked), together with vital events data such as births and deaths. Data from the 2021 Census are to be added soon. The ONS has recently completed a consultation exercise on the future of population and migration statistics. The proposals, if implemented, would see the census replaced with a system primarily based on administrative data, complemented by survey data and a wider range of data sources. This would have significant implications for the LS, as its current design is critically dependent on the decennial census to provide additional observations for the sample members. This paper - written independently of ONS - reflects on possible models for the future of the LS in a scenario in which a census did not take place. We look at those aspects of the census which seem hard to replicate in administrative data, especially those that may also be difficult to capture in surveys. We consider possible ways in which the LS may evolve into a hybrid census-administrative data data set, and set out advantages and disadvantages of different approaches.

See extended abstract

 Presented in Session P1. Fertility, Family, Life Course