The panel welcomed ONS proposals to take an active role in data linkage on migration across government departments, including setting up a cross-government working group.
The panel noted that ONS will need to work closely with other government departments to set standards for ensuring that newly emerging administrative systems are set up from the outset to produce relevant statistics, and should not assume this will happen naturally without a clear strategy and cross-government commitment to resourcing.
The panel recommended that ONS work with other government departments to explore how administrative data collection defines migrants (i.e. by country of birth, nationality, immigration status) in order to work towards more complete and consistent data in future years.
The panel believes that ONS should see external researcher data access as part of its strategic pillar 2, improving the quality of the methods – because external scrutiny of the data will help to identify problems and improvements.
The panel noted concerns that TLFS stocks estimates may not sufficiently capture the whole migrant population, especially newly arrived migrants, and suggests that TLFS and administrative data stocks estimates should be developed in tandem.
The panel would welcome input from the new National Statistician, when they are appointed, on how it can best guide ONS’ migration statistics strategy.
Introduction
The Chair opened the meeting and welcomed members, including new members Nicola Pearce and Sarah Montgomery from FCDO.
The Chair noted there were no outstanding actions from the previous meeting.
Key messages from Methodological Assurance Review Panel: Migration statistics sub-group
The Methodological Assurance Review Panel: Migration Statistics sub-group has not met since the last report.
Key messages from the Migration Statistics User Group
The ONS presented an update on the migration statistics strategy, due to be published in Autumn 2026, and the links with other core statistics including population estimates and projections. The strategy will support the aim of producing trustworthy, timely, high quality, long term international migration statistics drawing on administrative data. It will include plans based on a continuous improvement approach, local authority level estimates, temporary mobility statistics, population stock estimates, and data linkage capabilities over the period to 2031 and beyond. The group discussed the inclusion of metadata and documentation on quality, strengths and limitations.
The group discussed the challenges and opportunities for linking administrative datasets. The group discussed where ONS can make a unique contribution around migration estimates, migrant population stocks and understanding unauthorised migration, whilst working collaboratively with other departments where appropriate.
There was support within the group for exploring the creation of a dedicated data working group to consider data linkage opportunities, ethical considerations, data sharing challenges and potential approaches to improving migration-related data assets based on user needs.
The group received a presentation from the Home Office on the annual Migrant Journey Report, which tracks how migrants move through the UK immigration system over time, including route switching, settlement outcomes and retention patterns. The report was noted as a valuable source for understanding long-term pathways through the immigration system. Recent enhancements to the Migrant Journey Report, including additional breakdowns for work and family routes were felt to be particularly valuable and there were suggestions for further developments.
The group provided feedback on the current structure and content of the ONS long-term international migration bulletin. Users reported that the overview section and the detailed migration estimates sections were the most frequently used elements of the publication. Feedback on future development included the potential for longer time series in some breakdowns in the data tables, additional local-level statistics, and continued provision of detailed information on revisions and methodology changes.
The group noted an update from ONS that the Office for Statistics Regulation’s systemic review of long-term international migration statistics is expected to be formally closed following ONS addressing the recommendations made during the review process.
The group discussed future arrangements for the Migration Statistics User Group. Initial feedback indicated some support for retaining quarterly meetings while alternating between the current format and meetings focused primarily on user presentations and discussion. A decision will be taken on the frequency and format of the meetings shortly.
ONS migration statistics strategy
ONS presented an overview of the main themes of the migration statistics strategy along with an update on progress made on its development since the last meeting. Comments and feedback previously given by the panel have been incorporated and further user engagement with both MSUG and the Office for Statistics Regulation (OSR) has been carried out. Areas highlighted for discussion included: the development of migration population estimates; statistical input to the design of administrative data sources; and accessible communication with users.
ONS noted that a draft of the strategy document will be shared with panel members for more detailed comment shortly after the meeting. The panel was then invited to provide advice on how to ensure the successful delivery of the plan.
Action: ONS to share draft strategy document with NSAP members.
The panel highlighted that to achieve statistical input at the design stage, ONS needs to be proactive in communicating requirements or potential uses for administrative data to the developers of operational systems across government. They also suggested potential models for collaboration such as secondments and sharing knowledge of data and systems to help build appropriate business cases for statistical needs to be reflected in system designs.
The panel noted a concern about relying on Transformed Labour Force Survey (TLFS) data to produce migration population estimates (stocks) as it may not fully capture the whole of this population, particularly new arrivals. ONS confirmed there is also a longer-term aim set out in the strategy to develop an administrative data-based method, but that the TLFS has the advantage of collecting information on country of birth, which is not available from administrative sources. The panel suggested that a) it would be sensible to develop both approaches in tandem and b) ONS should also work with other government departments to explore the feasibility of administrative data sources defining migrants in a consistent way in terms of country of birth, nationality, etc. in future.
The panel also noted the importance of external researcher access to microdata for providing transparency, external scrutiny and additional insights. They recommended it be specifically included in strategic pillar 2 of the strategy.
ONS also put forward a proposal to set up a cross-government data linkage working group to promote the benefits and opportunities for sharing linked data such as enabling more international migration research across government and filling known evidence gaps. This would be with the initial aim of understanding the practical and ethical challenges and likely feasibility. The panel welcomed this proposal and indicated an interest in further involvement with this group in future. They also raised a question around whether anyone in Cabinet Office or HM Treasury has a central role in government for data sharing or data linkage.
Action: ONS to investigate if there is a central government contact for data sharing or data linkage.
Review of functioning of the panel
The chair introduced an agenda item to briefly review the functioning of the panel as it is now approximately one year since it was set up. Thoughts were requested from members on any proposed changes and whether the panel is meeting its aims.
Members indicated that it would be helpful to receive drafts of papers and/or slides further in advance of the meeting where possible to allow additional time to provide considered feedback.
The remit and scope of the panel was discussed in relation to areas of the ONS migration strategy that include cross-government collaboration, for example on data linkage. ONS indicated that regularly reviewing the remit of the panel should be considered in light of ongoing changes in the migration statistics landscape and potential new opportunities. However, need to consider any potential changes carefully given the original remit of the group to provide advice to the National Statistician.
Panel members suggested that it would be useful for the group to also review technical details and methods, in addition to general items such as strategy. While there may be some potential overlap with other groups, members indicated that some additional understanding of technical details and proposed new methods would help them to provide focused strategic advice and recommendations.
The panel also noted that they would welcome input from the new National Statistician, when they are appointed, on how it can best guide ONS’ migration statistics strategy.
