The importance of population and migration statistics
Population and migration statistics are a vital input into decision-making by public, private, and voluntary sector bodies and they help all of us understand better the evolving society within which we live. They help us to better understand the population and migration of individuals in the UK. The Office for National Statistics (ONS) produce statistics that are a trusted source of official population and migration data. Population and migration statistics provide evidence to central and local government to ensure public services are delivered, and that resources are allocated effectively.
Why population and migration statistics are evolving
At the ONS we want to ensure population and migration statistics are available in a timely fashion, to meet the needs of our users, and that the system for producing these statistics is flexible and inclusive, maintaining a stable level of quality over time and inspiring user confidence.
In recent years, technological advances and the greater availability of administrative data (for example, tax and benefits records, visas issues and NHS data) have meant the ONS has been able to demonstrate the viability of using updated approaches to estimate the population at a more consistent level of accuracy and more frequently.
Policy users and decision makers have often told us they would benefit from more frequent and timely statistics. Greater use of administrative data will help us to meet these needs, and the ONS has carried out a programme of research to develop its population and migration statistics by further expanding the range of data sources it uses. The following section provides an overview of the research that has informed the UK Statistics Authority’s recommendations.
Our research that has informed the UK Statistics Authority’s recommendations
We have shown the potential of administrative data to improve the level of accuracy over time in our population estimates. Migration estimates that are based on administrative data allow us to respond to the difficulties of estimating internal and international migration. We have developed methods for producing information about the population more frequently. These methods also allow us to rapidly respond to events such as the coronavirus (COVID-19) pandemic by providing essential data to inform national strategy.
These methods will also offer further insights into our rapidly changing society, as administrative data reach their full potential over the next decade. We have produced admin-based population estimates (ABPEs), which demonstrate the potential to produce more timely estimates of the population, compared with our current approaches.
We aim to meet the standards expected of accredited official statistics and will seek accreditation once we have developed the appropriate methods for producing the ABPEs. We will continue to consult with our users about our approaches. For more information, please see our Local Authority Case Study published in 2024.
You can read more about the methodologies we are developing on our Methodology and quality strategy web page.
To learn more about why we are changing the way we produce statistics, you can watch our video.
You can stay updated about our work on our Progress updates and Research outputs using administrative data pages.
The consultation and recommendation on the Future of Population and Migration Statistics in England and Wales
Throughout our research into a population and migration statistics system that is based on administrative data, we have engaged with users across government, the public sector, businesses, the third sector and academia. As part of this engagement, we conducted a public consultation that opened on 29 June and closed on 26 October 2023.
In support of the consultation, we held a series of roundtables, webinars and meetings with a diverse range of users from the private and public sectors, as well as charities and community groups. We asked for their views on how our proposals for a new approach to population and migration statistics in England and Wales could meet their needs, compared with the current approach.
More information about the consultation outcome and the recommendation can be found on our Consultation publications and updates web page. We will continue to work with users across all sectors as this work progresses.
If you would like contact us about our future research plan, please email fpms.engagement@ons.gov.uk.
The future of UK population and migration statistics
The ONS has responsibility for the census and population statistics for England and Wales. Therefore, the consultation and subsequent National Statistician's recommendation relates to England and Wales, in the context of the wider UK statistical system. We are working in partnership with the Welsh Government.
The National Records of Scotland (NRS) and the Northern Ireland Statistics and Research Agency (NISRA) are developing their plans in parallel. Decisions on the future of the census in Scotland and Northern Ireland will be made by the relevant Ministers, based on advice from their statistical authorities. Statisticians across the UK are working together to ensure each nation has the information needed to inform these decisions and support UK coherence.
The National Statistician, registrars-general and chief statisticians signed the Statement of agreement: cooperation on future UK population and social statistics in November 2022, available on the UK Statistics Authority website. This will support the production of coherent UK statistics, comparable between the different parts of the UK, into the future.
The implementation of the agreement is being reviewed annually by the signatories and there is ongoing engagement between all four nations.
What are administrative data?
Administrative data are data that have primarily been collected for administrative or operational purposes. They are made up of information that we all provide when we access public services like the tax, benefits, health and education systems. For example, we use the numbers of registered births and deaths along with health and census data, to create statistics on health inequalities in different social classes, based on a person’s occupation.
Linked data
Data or record linkage is a method of bringing together information about the same entity from different sources to create a new, richer dataset. Data linkage is now commonly used for improving data quality and integrity, to allow the reuse of existing data sources for new studies, and to reduce the cost and effort in data acquisition.
How we protect the confidentiality of data
The ONS has a proven history of protecting sensitive data. This has been built over many decades of delivering the census in England and Wales and the UK’s biggest regular household surveys. For more information, see our Data strategy web page.
The ONS follows data protection legislation. This means that when we consider new uses of personal data, we ensure the use is necessary, proportionate and transparent before proceeding. When we identify potential risks, we also produce Data Protection Impact Assessments. These are necessary to understand and mitigate data protection risks.
We protect administrative data to the same high standard as census data. It is a legal duty to maintain confidentiality under the Statistics and Registration Service Act 2007 and the Data Protection Act 2018. Strong sanctions are in place to stop anyone from disclosing or seeking to disclose personal data.
Access to person identifiers, such as name and detailed address, are restricted to a small number of ONS employees. Once data are linked, person identifiers are removed from the data used for wider statistical analysis.
All our procedures, systems and staff protect both the data and your confidentiality by law, so no one can be identified from the statistics we publish.