Dear Jonathan

ONS response to OSR’s review of population estimates and projections

Many thanks for providing a response to the Office for Statistics Regulation’s May 2021 review of Population Estimates and Projections produced by the Office for National Statistics (ONS). The package of outputs, including the detailed article and blog, demonstrate your commitment to building upon our findings to improve the public value of population estimates and projections.

We are encouraged by the focus on improving methods, enhancing communication and active engagement. It has been good to see the steps ONS has already taken to engage with users since we published the review, and we welcome the theme of working with local experts and users appearing throughout the different workstreams highlighted in your response. As stated in our review, we would encourage ONS to continue to work with the devolved administrations to identify opportunities for collaboration and efficiency in addressing our recommendations and determining a long-term solution to some of the issues we highlighted in our review.

Building on these positives, you should continue to be ambitious in delivering the work. We recognise that many of the improvements to methodology are reliant on Census 2021 data being available, so it is good to see that work to develop guidance and presentation of uncertainty has been prioritised in the meantime. We would urge you to identify the quick wins that can be achieved in the next few months. For example, since publishing our review, users have expressed interest in ONS producing fan-chart visuals for local authorities as well as including a list of the types of administrative data which are used for quality assurance within the supporting guidance.

Similarly, we welcome your plans to review how recent work using administrative sources (for example, Home Office Exit Checks, Higher Education Statistics Agency and Pay As You Earn data) can provide insights on student population movement in to and out of local areas and explore how student populations change in combination across our population estimates and projections. As well as sharing the insights from this work with experts, we would encourage you to publish regular updates on the emerging findings from this work to help inform users of the possible areas which may need to be addressed with regard to cities with large student populations. To manage users’ expectations, it may also be worth publishing a timeline of how your plans for addressing our review’s findings relate to Census milestones.

We welcome the commitment to report back to us on a quarterly basis and we look forward to the first update in October 2021.

Yours sincerely


Ed Humpherson

Director General for Regulation


Related Links:

Jonathan Athow (ONS) to Ed Humpherson: OSR review of Population Estimates and Projections

Review of population estimates and projections produced by the Office for National Statistics