Correspondence with Coventry City Council regarding 2021 Census information

​FOI Ref: FOI/2021/3343

You asked

I wish to understand the evolution and refinement of the 2021 census. Sir Ian Diamond, the National Statistician has stated that every council will be involved in testing the provisional outcomes and each council would have a census liaison manager and an assistant census liaison.

I would like to see the following:

1) Any correspondence between ONS (or its census agents) with Coventry council since 1 Jan 2020, including any suggested changes to the provisional figures.

2) Any guidance which ONS has supplied for reviewing and testing the provisional figures, particularly about:

• The roles of the census liaison manager and assistant census liaison, and
• Any local data which would be considered relevant in arriving at a final census figure.
• Any examples of how the provisional figures might be adjusted and what evidence should be supplied.

3) Any correspondence with other stakeholder bodies (such as NHS, police, fire, environment, or academics) about the provisional census figures for Coventry.

4) The provisional census figures for Coventry council.

5) I would like to know, as a positive or negative number, the size of any adjustment proposed to the provisional population figure for the city, and the rationale for that adjustment or departure from the provisional figures (even if the provisional figure is not disclosed, I would like the figure for any proposed change - up how much? Down how much?) If there is any information relating to accepting or rejecting that proposed change, I would like that as well.

We said

Thank you for your request.

In response to part one of your request please find attached correspondence with Coventry City Council since January 2020. We have redacted personal data in accordance with section 40(2) of the Freedom of Information Act 2000 (FOIA). We have provided only communications specifically sent to Coventry City Council, rather than generic census communications which were sent to all local authorities in England and Wales, as we didn't consider these in scope of your request. There have been no communications regarding the changing of provisional figures for the reasons set out below.

In response to the rest of your request (sections 2 to 5), this is information not held. We are at the beginning of this particular engagement exercise, with a view to share provisional estimates in February 2022. Therefore, the information you have requested has not yet been created, if it will be created at all. To note, we would only release estimates prior to formal publication in certain circumstances in line with the trustworthiness pillar of our Code of Practice for Statistics. More information regarding this can be found on p.19-20 of the linked Code.

In January 2020, we published our 'Approach and processes for assuring the quality of the 2021 Census data' in which we detailed checks we would undertake to validate the census estimates and comparator data sources we would use. We also invited readers of the paper to suggest proposals for other analyses or data sources we could adopt in the validation of the estimates and suggestions of evidence that would provide reassurance on the reliability of the census results. These suggestions can be sent to census.quality.assurance@ons.gov.uk.

The decision to provide local authorities (including county councils and combined authorities) across England and Wales with early access to provisional census population estimates as part of our quality assurance (QA) process, but not to widen that access to everyone with an interest in the figures, was based on:

•       The additional value that these organisations can provide to the QA (given the arrangements described in the previous paragraph);

•       The resource required to administer the process and investigate any feedback received; and

•       The need to implement a fair process which does not implicitly place greater value on accurate estimates for one area over another and

•       A recognition that estimates are still in development so widespread access increases the risk of misleading conclusions being drawn.

The Code of Practice for Statistics enables us to provide early access to these provisional figures to support our QA. Only those individuals supporting us in the QA will be able to access the data and it cannot be shared more widely or for any other purpose including within the organisations with which the data have been shared. Any other use could be misleading and result in a loss of public trust. Final census statistics will be published after numbers have been finalised and the QA process completed. Those taking part are required to sign a Non-Disclosure Agreement and are required to follow strict security and data management rules.

Our QA covers a series of extensive checks and involves validating against a wide range of sources including ONS statistics, surveys and administrative data. Should inconsistencies between the indicative census estimates be seen, highlighted by local area knowledge and comparison with locally held sources, we may investigate further as part of our quality assurance.

The aggregate data provided to local authorities will be for a limited number of variables, and will be made available to them in February 2022. The data provided will not be the final numbers. The data is subject to change as further statistical methods will be implemented, for example finalising adjustments for non-response and statistical disclosure control. We have published a detailed description of the Census statistical design.

As noted, if there are suggestions for information that might be valuable for our QA we welcome suggestions.

Please note that we have considered your request under the Freedom of Information Act as we do not consider the information requested to be environmental information. However, similar exceptions apply within those regulations for personal data (regulation 12(3)) and for information not held (regulation 12(4)(a)).