1. Overview
This review provides recommendations and a framework that will help the UK statistical system make the step change needed to deliver UK-wide comparable statistics and data on priority topics. Given the long-running and complex nature of this issue, our recommendations are challenging and will require careful thought and oversight to successfully deliver. But in our view, they are all necessary to drive the changes needed to address the issues highlighted in recent reviews and, importantly, meet the needs of statistics users.
Why we did this review
The May 2024 Independent Review of the UK Statistics Authority (referred to herein as the ‘Lievesley review’) and the May 2024 Public Administration and Constitutional Affairs Committee (PACAC)’s report Transforming the UK’s Evidence Base highlight that the lack of comparable UK-wide statistics is hindering meaningful comparisons of performance and outcomes across the UK. The PACAC report recommended that OSR review and publish a report on the adequacy of UK-wide comparable data, by themes. This report forms our response to this recommendation.
The UK Statistics Assembly held in January 2025 also highlighted the importance of the statistics system recognising the need for UK-wide statistics and advocating for, and supporting, harmonised data where desirable. The report from the Assembly recorded this as a high priority.
Highlighted findings
Crucial to our work on this topic has been differentiating between coherence (whether the extent of similarities or differences for statistics and data are fully documented and explained) and comparability (the degree to which data can be compared across different geographies over time). We found more focus is needed on comparability as opposed to merely coherence.
To support this, and drawing on work by The Fraser of Allander Institute (as part of the research programme of the Economic Statistics Centre of Excellence) and internal guidance issued by the then-Department for Levelling Up Housing and Communities in 2023, we set out a new comparability framework tool (Annex A) to support the UK statistical system and users to better understand comparability.
Changing landscape of data sources
The data underpinning UK statistics are changing. We increasingly see challenges to traditional survey data collection in the context of reducing response rates and more use of administrative and other big datasets.
There are different governance and legal gateways for data sharing, technological capability, and people and financial resources available to support comparable UK statistics and data. We recommend a review of the legal frameworks relating to data sharing and access to identify opportunities for legislative changes to level the playing field in data sharing, access and capability across the UK nations.
Understanding user needs and comparability
There is a need to look more widely at user needs and consider a ‘public good’ lens for UK-wide comparable statistics and data. The absence of a joined-up picture of users’ needs beyond government at the national, regional and local levels inhibits the effective prioritisation and development of comparable UK-wide statistics and data for the public good.
We recommend a comprehensive cross-UK review of the needs and uses for UK-wide comparable data, based on an assessment of comparability using our comparability framework. This review can then inform a strategy to produce and maintain comparable UK-wide statistics and data on selected priority measures at national, regional and local levels.
Strengthening strategy and governance
The Concordat on Statistics is the key framework for statistical cooperation across the UK. The current arrangements have delivered significant programmes of work and improved understanding of the extent of coherence or comparability. But stronger arrangements are needed to improve the availability of comparable UK-wide statistics and data on priority topics. We recommend that the UK statistical system conduct a review of the strategic effectiveness of current governance arrangements for producing comparable UK-wide statistics.
Overcoming finance and resource barriers
There are inequities in the resources, capability and infrastructure available across the UK system to achieve UK-wide comparable statistics and data.
We recommend that the UK statistical system should seek cross-UK political commitments to adequately finance meaningfully comparable statistics on agreed priority measures at national, regional and local levels. The 2031 Census recommendations offer an imminent opportunity to initiate such conversations within the framework of a long-term strategic plan that utilises survey, administrative and third-party sources.