Quarterly update on Population and Migration Statistics: October 2024

In June we published an article, entitled What is coming up on population and migration statistics, which provided an overview of upcoming publications as we make improvements.

We have continued to develop our plans and engage with users of our population and migration statistics following our Consultation on the future of population and migration statistics in England and Wales, and ahead of the Recommendation on the future of population and migration statistics being published over the next few months. This article provides an update on our plans relating to migration and population statistical releases.

On 15 July we published Population estimates for England and Wales: mid-2023, which included a comparison with our updated mid-2023 admin-based estimates. We also published Population estimates for the UK, England, Wales,  mid-2011 to mid-2022, a statistical design article setting out how we are developing population and migration statistics using administrative sources, and an accompanying blog to provide a summary, with links to other useful information.

The release of population estimates was widely reported by media outlets, demonstrating the continued importance of these statistics in wider public discourse in addition to the wide range of uses within central and local government, other public bodies, academics and charities.

The Office for Statistics Regulation (OSR) also published its Admin-Based Population Estimates (ABPEs) phase one assessment report on 15 July. The report highlights areas where the Office for National Statistics (ONS) needs to make more progress, while also highlighting that "the approach promises to deliver significant benefits for users." 

On 28 October, we published our action plan in response to OSR’s assessment of ABPEs, which outlines how we are addressing the areas highlighted in the OSR report and giving more detail on our plans over the next 12 months. Our ambition remains to publish ABPEs in the Summer of 2025 as the preferred measure, but this is subject to meeting the acceptance criteria which we plan to share in January. To enable us to focus on the activity required to transition to ABPEs becoming the preferred measure, we will not publish provisional ABPEs this winter. It remains our intention to publish provisional ABPEs approximately six months after the year end once we have moved to ABPEs as preferred measure of the population.

To support our development of ABPEs and as part of our ongoing engagement, we have invited 15 local authorities (LAs) to work closely with us to further develop the ABPEs (and their components such as internal and international migration) along with the admin-based living arrangements. Our aim is to ensure local authority users understand what we are producing, how and why and have confidence in our approach for evolving our population and migration statistics. This should help us ensure population estimates meet the needs of local authorities as well as being an important aspect of our quality assurance of the new approach. It is also an opportunity to learn about local data sources and benefit from local insights.  

The 15 local authorities were chosen to ensure we look at a range of different demographic characteristics, for example:

• student areas

• urban and rural areas

• areas with transient populations, such as seasonal workers,

• areas that had previously engaged with both the Census 2021 and Dynamic Population Model

We have published our engagement plan for ABPEs and will continue to update users. 

This section outlines the continued work on international migration.

The November long-term international migration publication will include improvements to the assumptions that are used for provisional estimates of migration. While we estimate migration based on those who arrive or leave for 12 months or more, we do not have 12 months of travel data for all migrants when we produce provisional estimates. Instead, we use assumptions about people's expected length of stay or departure, based on past trends. This is used to adjust the most recent data and provide a provisional estimate for the most recent time period.

From November, we will look at past trends by age, nationality, and reason for migration, and apply these differently to people arriving on different visa types, with different ages and nationalities. This will result in our assumptions better reflecting the different behaviours we see for these different groups. The November publication will also include improvements to non-EU methods, including a better understanding of those who move to new visas and therefore remain in the UK, and those who leave the UK long-term before their visa expires.

We are also working on improvements to our approach to estimating long-term international migration for EU and British Nationals. These new methods and data sources are currently being assured by experts, subject to this work, our intention is to implement changes for our May publication.

We have recently published our Methodological Assurance Review Panel, MARP information, which includes the research we have done on these new methods for EU nationals and British Nationals. For more information on the definition of a "British National", see the discussion in the UK Statistics Authority's Methodological Assurance Review Panel - Agenda and Minutes 20 August 2024.  

The information below sets out our plans for the next 12 months:

Autumn 2024 

• Our Rebased population estimates, broken down into small geographical areas (output areas, electoral, health, parliamentary constituencies and National Parks) 2012 to 2020 will be published.

• The admin-based population estimates: local authority case studies, England and Wales, mid-2023 will be published by the end of the year to help users understand differences between admin-based and official mid-year estimates.

• We will publish Provisional June 2024 long-term international migration, including updated estimates 2021 to 2023, on 28 November, which will include improvements to the assumptions used in our provisional estimates and to non-EU methods.

• Ahead of providing an update on our plans for estimating non-UK-born population in 2025, we aim to provide experimental, provisional estimates for the non-UK-born population of England and Wales, to June 2023.

• We will continue engagement to support our efforts to best meet user needs, this will include working with Central Government departments, Devolved Governments and other organisations; to support this, we have published our ABPE engagement plan as a part of the response to OSR's assessment of ABPEs.

• On 24 October we held the 2024 Migration Statistics User Forum and our series of webinars will continue following the release of our next long-term international migration publications; visit Eventbrite to register for the Long-Term International Migration Statistics Webinar, taking place on 3 December 2024.

• A UK Coherence Group will bring together colleagues from England, Northern Ireland, Scotland, and Wales to progress plans to ensure that population estimates are robust and provide what users need from UK-level statistics.

Winter 2024 to 2025

• Our upcoming National population projections: 2022-based release will be published on 28 January 2025.

• We will outline the criteria that must be met for us to take the decision that Admin-Based Population Estimates (ABPEs) will become the preferred official estimate of population for England and Wales, replacing the current methodology: feedback from users will be welcomed throughout this process.

• Following engagement with a wide-range of stakeholders, we will publish an update on plans for how revisions will be managed in the admin- based population and migration system.

• Aiming for an in-development version of the Admin-Based Census (ABC) to be available for users within the Integrated Data Service.

Spring 2025

• We will update on our progress towards using new data sources for estimating British Nationals and EU migration for international migration.

• We will set out the steps we are taking to add population attributes to the Admin-Based Census, which will provide an overview of the main milestones and deliverables for the next years to deliver this development work.

• We will provide an update on our plans to produce estimates of non-UK-born population.

• Long-term international migration estimates will be released for YE December 2024, aiming to make use of further administrative data sources, and improving methods for estimates of all visa holders.

• We are aware of the user need for statistics on short-term international migration and will be continuing to explore administrative data sources as an alternative to the previous International Passenger Survey (IPS) based estimates.

Summer 2025

• We are working to meet the standards expected of accredited official statistics by summer 2025 and, subject to meeting the acceptance criteria, plan to publish ABPEs as the official estimate of the population, mid-2024, for the first time.

Autumn 2025

• We will aim to publish small area estimates that are consistent with estimates for LAs and larger geographies; by summer 2025, we will provide information about which methods will be used for estimates for different geographies.
• Long-term international migration estimates will be published for YE June 2025; our intention is to move to annual methods changes, with substantial improvements having been made in Spring 2025.

Please sign up to our monthly newsletter for updates on publications and events, including our planned new programme of webinars on population and migration statistics.

We are committed to sharing an update to this article on a quarterly basis, as development and analysis progresses. In line with best practice in continuous improvement on statistical outputs, this page supports our ongoing commitment to engage with users as we develop our outputs. We will continue to engage with our users in a range of ways, such as bilateral conversations, user engagement groups, and conferences.

User feedback plays an essential part in our ability to improve our statistics. Please email pop.info@ons.gov.uk with any questions or feedback.