This report covers the work of the Methodological Assurance Review Panel (MARP) from 1 October 2024 to 30 September 2025. The panel remained unchanged during the year, with Sir Bernard Silverman as the chair, and Professor Ana Basiri, Professor Oliver Duke-Williams, Carl Emmerson, Professor Nik Lomax and Professor Natalie Shlomo as panel members. In that period, the panel met four times and considered additional papers by correspondence. The role of MARP is to formally address requests from the National Statistician. Following Sir Ian Diamond’s resignation, it continues to support ONS leadership, fulfilling the established terms of reference.
Papers considered by the panel included a proof of concept for the Longitudinal Population Dataset, a proposal considering Differential Privacy suitability for Statistical Disclosure Control, and an options paper for refining the excess mortality methodology. Other topics assured included hierarchical models and aggregate uncertainty in the Dynamic Population Model, and coverage estimation for admin-based population size estimation.
In June 2025, the UK Statistics Authority endorsed the National Statistician’s recommendation to commission a mandatory questionnaire-based census in 2031 as well as to continue to develop the use of administrative data to provide more frequent and timely estimates. This recommendation included a statement of advice received from MARP. Following the recommendation, the panel considered discussion papers for the statistical design for Census 2031, and reviewed proposed evaluation criteria for the 2031 Census Topic Consultation. The panel also held a workshop discussing innovation ideas for the 2031 Census.
In addition to formal papers, the panel considered items and updates on matters seeking early assurance and review ahead of full paper publication. Following recommendations from the Lievesley Review, it has reviewed its membership processes, and given other direct feedback about ONS’s use of the panel.
The panel continues to examine and comment on every item brought by ONS, both in preparation ahead of meetings, and at meetings themselves, making recommendations for the ONS and when necessary giving actions for items to be brought back, or further updates to be given to the panel. For a full list of papers and topics assessed during this period, and the minutes covering all items short of a paper, please visit the MARP minutes and MARP papers pages.
Some of the work of the panel was delegated to specialist subgroups. The subgroups had delegated authority to report directly to ONS, but the main panel was given regular updates on the work of the subgroups. This has now been formalised through a working protocol for the subgroups. In particular any subgroup which is not a short-term “task and finish” group is chaired by a member of the main panel.
The Labour Market Statistics subgroup, with members Professor Ray Chambers and Professor James Brown, published key findings in April 2025, following an initial report in December 2024.
The Dynamic Population Model subgroup was established in May 2025. The chair is Professor Ana Basiri and the other members are Dr Fred Piel, Professor Jon Forster, Professor George Ploubidis and Professor Arkadiusz Wiśniowski. The subgroup has been established to provide independent, expert technical assurance on the development of ONS admin-based population estimates (ABPEs). This will ensure the statistical methods underpinning the Dynamic Population Model are robust, transparent and continuously improving.
A Migration Statistics subgroup was established in July 2025. The chair is Professor Nik Lomax and the other members are Dr Marie McAuliffe, Professor Arkadiusz Wiśniowski, Professor Jakub Bijak and Georgina Sturge. This group provides independent, expert technical assurance on the methodology used to produce international migration statistics.
There were, in total, six subgroup meetings, with further items considered by correspondence. Papers were reviewed detailing methodologies across ONS work areas, with a continued focus on the Future of Population and Migration Statistics (FPMS) programme, as well as increasing attention in the latter part of the period to Census-related topics following the National Statistician’s recommendation.
MARP had previously assured content on FPMS and made a statement on that topic, which was published in this period. Additionally, via the Labour Market Statistics subgroup, MARP published statements concerning the Transformed Labour Force Survey (TLFS) and Labour Force Survey (LFS) recovery plan. In December 2024 an initial review covered emerging issues from the methodology review of the TLFS and LFS. Following further work, two publications followed commenting on the Labour Force Survey Recovery Plan, and comments on proposals for the design of the Transformed Labour Force Survey.
Overall, the panel is satisfied that ONS has taken account of recommendations, guidance and challenge, both from the main panel and from the subgroups, and that future planning reflects the needs of the panel and its subgroups.
Bernard Silverman
Chair of the Methodological Assurance Review Panel
1 October 2025