Overview
The 2021 England and Wales Census statistics, produced by the Office for National Statistics (ONS), are published as accredited official statistics.
The census is one of the most important sources of data and statistics, informing decisions about almost every aspect of life within the UK. It gives users access to important information on the people and households of the UK and helps us better understand the places in which we live and work.
Why we did this review
The Office for Statistics Regulation has conducted assessments of the censuses produced by the Office for National Statistics (ONS), the National Records of Scotland (NRS) and the Northern Ireland Statistics and Research Agency (NISRA). It is essential that the data and statistics from the censuses are reliable and provide valuable insights by meeting the rigorous standards of Trustworthiness, Quality and Value outlined in the Code of Practice for Statistics.
Our census assessments have been conducted in three phases. In October 2019, we published our reports on Phase 1, focusing on the planning and consultation activities undertaken by the census offices across the UK. In November 2021, we published our Phase 2 Assessment reports, focusing on the strategies for developing and providing outputs for both the England and Wales Census 2021 and the Northern Ireland Census 2021. Our Phase 2 Assessment report for Scotland Census 2022 was published in April 2023.
Following concerns raised by users, we reviewed statistics on gender identity based on data collected as part of the 2021 England and Wales Census. ONS requested and we agreed that these statistics should not be accredited official statistics. Our review found that that the issues we identified were limited to the statistics on gender identity and did not impact the census as a whole. We recently published an update on this work (insert link to letter when published). Given that separate review and its conclusions, this report does not further consider gender identity statistics from the 2021 Census.
This report covers the third and final phase of our Assessment, focusing on the England and Wales Census 2021. In 2022, the day before the first release for the 2021 Census in England and Wales was published, we wrote to ONS confirming these statistics’ National Statistics designation (now referred to as accredited official statistics). Our judgement was based on a range of evidence evaluated during phases one and two and ONS’s commitment to ensure that the Census 2021 statistics for England and Wales would be of high quality and meet the wide and varied needs of users of these data.
This report therefore focuses on the extent to which ONS fulfilled its commitments from 2022 and met the needs of statistics and data users with the 2021 Census for England and Wales outputs.
Highlighted findings
ONS delivered Census 2021 outputs for England and Wales in a timely and accessible way. The range of products, supported by ONS’s communication activities, allowed users to maximise the public value of census data to meet their individual needs.
The 2021 Census achieved high response rates with sound methods. ONS carried out extensive quality assurance of the estimates, capturing an accurate picture of England and Wales at that time.
ONS has published a wide range of information on the quality of the census. However, navigating the quality information is particularly challenging, and user feedback on this was disappointing.
Census 2021 was carried out during the COVID-19 pandemic. ONS has looked at the impact of these unique circumstances in some specific areas (for example, travel to work). ONS has committed to providing users with further detail to fully support the use of these statistics.
ONS carried out extensive user engagement through a range of channels, both during the development of the census and the delivery of the outputs. It also went to great lengths to reach users that it wouldn’t normally engage with. However, ONS could do more to provide feedback to users when comments are not taken forwards.
Although ONS has recently updated users on its plans for UK-level census outputs, ONS has not published any such outputs.
Our judgment
ONS has responded well to the requirements of our Phase 2 Assessment, but there remain some gaps to be addressed. We recognise ONS’s effective user engagement, the provision of extensive documentation on quality and methods, and the publication of timely, accessible and flexible census outputs. However, there are areas where ONS could have provided more joined-up and detailed information for users, particularly around the impact of the pandemic and ONS’s plans for UK census outputs.
We have set out one requirement and six recommendations for ONS to take forward in this report. We can reconfirm the accreditation of the 2021 Census in England and Wales outputs, excluding gender identity statistics, subject to ONS meeting our expectations for the requirement.
Next steps
We expect ONS to meet the requirement set out in this report within 6 months and we will continue to engage with ONS during this process.
In addition, we expect ONS to take forward actions in response to our recommendations as part of its planning for the future provision of population statistics for England and Wales. It is important that ONS continues to identify and evaluate what lessons can be learnt from Census 2021. We will review responses to the recommendations set out in this assessment report when we carry out future reviews of population statistics.
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