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Dear Mr Drakeford,
Recommendation on the Future of Population and Migration Statistics
As you will know, the 2018 White Paper ‘Help Shape Our Future’ included the commitment to present a recommendation to Government on the future of population and migration statistics. This would respond to the Government ambition, as set out in 2014, that
“censuses after 2021 will be conducted using other sources of data and providing more timely statistical information”.
In March 2025, the then National Statistician, Sir Ian Diamond, made a formal recommendation to the UK Statistics Authority Board which we have accepted and adopt as our own recommendation. Central to that advice, and the Board’s endorsement of it, has been:
- the extensive research that the ONS has undertaken and published on the use of administrative data for population and migration statistics;
- the ONS’s understanding of legal and privacy issues, adhering at all times to the ONS’s Data Strategy to ensure rigorous data security and protection;
- the ONS’s research to understand public attitudes to administrative data and data linking, and its engagement with the National Statistician’s Data Ethics Advisory Committee;
- the thorough assessment it has made of the opportunities and risks involved;
- the findings of the wide-ranging public consultation process that it undertook in 2023; and
- the assessments that it requested from the Methodological Assurance Review Panel (MARP) and the National Statistician’s Inclusive Data Advisory Committee (NSIDAC).
Sir Ian Diamond since stepped down as National Statistician on 9 May 2025. The Acting National Statistician Emma Rourke endorses the recommendation, and the Board continues to support it enthusiastically. The Board of the UK Statistics Authority is satisfied that the ONS has carried out a thorough public review of the future provision of population and migration statistics in England and Wales.
The public consultation undertaken to inform this recommendation found widespread agreement that more frequent and timely estimates of the population would be valuable to a wide range of users, including local and national policymakers, providers of public services, decision-makers in the private and voluntary sectors, and researchers and citizens seeking to understand our evolving society and economy better.
But respondents to the consultation, along with MARP and NSIDAC, identified several requirements that would need to be met for an administrative-based system to satisfy user needs in a robust and sustainable way.
Meeting these requirements will require additional work by the ONS, but also significant supporting action from Government, notably to improve and guarantee the flow of the necessary administrative data. The Authority Board, users and the public would need to be assured that these requirements are met before we could be confident of relying on a primarily administrative-based approach.
This is reflected in the core elements of the recommendation attached. These are:
- that the UK Government commission and resource the ONS to conduct a mandatory questionnaire-based census of the whole population for England and Wales in 2031. This should support coherent UK outputs and maximise the benefits from the ONS’s work with administrative data to date, enabling further delivery of such benefits in the future.
- that the UK Government commission and resource the ONS to develop statistical outputs using administrative data which provide more frequent estimates and are inclusive in representing society. This should include an administrative-based census of the population.
- that the UK and Welsh Governments provide a commitment to the regular, reliable and ongoing flow of the critical administrative datasets required, ensuring that data owners deliver on that commitment, and invest in the required improvements to those sources and address the known points of friction that prevent data transfer.
The delivery of a census in 2031 will facilitate the ongoing partnership between the Welsh Government and the Office for National Statistics to develop high-quality Welsh language statistics that meet user needs.
I have written to commend this recommendation to the Parliamentary Secretary in Cabinet Office and now await the UK Government’s response.
Yours sincerely,
Sir Robert Chote
Chair