The indisputable value of statistics, data, and analysis to inform the most important decisions we face as a country has been clearly demonstrated in the policy challenges during my five and a half years as National Statistician. Those challenges have also shown the importance of timely data. I am proud of how the Office for National Statistics (ONS) has responded in providing high-quality statistics to meet urgent policy needs.
Since 1801, the census has been a crucial part of the evidence base for national and local decision-making. Taking place almost every decade, the census of population and housing has reached every part of England and Wales, providing vital information about the way we lived at each point in time. Census 2021 was a great success, with very high response rates nationally and locally. It delivered a wealth of high-quality data more quickly with greater flexibility for users than ever before.
The census has evolved over time, both in the questions we ask and the statistical methods we use to produce census estimates. Census 2021 was the first digital-first census, with nearly 9 out of 10 households completing their census online. We also made more use than ever before of the information that public sector organisations hold about people, alongside our wider research into how this administrative data can be used to provide more frequent and timely data in future. The UK Statistics Authority's recommendation, published alongside this report, proposes holding a 2031 census while maximising the growing power of administrative data to support and develop the admin-based population and migration statistics system. This would provide users with the granularity they require, with an increased understanding of changes to society in the intercensal years.
While preparing for Census 2021, we responded swiftly to the data needs of the nation in the face of the coronavirus (COVID-19) pandemic. We did this both with new and adapted surveys, monitoring the pandemic and its impact, and with analyses based on 2011 Census data. We made exceptional early use of data from Census 2021 to update these pandemic analyses and to inform government policy on rising energy costs and the response to Russia's invasion of Ukraine.
The most important thing about a census is, of course, the data that come out of it, which inform decision-making across the public, private, and charitable sectors. The estimates from Census 2021 were not only more timely than ever before, but also more flexible and accessible for users, catering for users with a wide range of needs and expertise. Through our "Create a custom dataset" tool and a range of other datasets, we enabled users to explore for themselves census data across most topics and levels of geography to meet their needs, while keeping individuals' data safe. Meanwhile, a range of products from games to innovative data visualisation brought the data to life, and our analysis articles explored them in more detail.
Our Census 2021: General Report for England and Wales describes how we designed and delivered the census, from the 2014 decision to hold an online-first census, through to the publication of census data in 2022 and 2023.
A successful census relies on the contributions of many people and groups, for which I would like to record my personal gratitude. These include our colleagues in the Welsh Government, National Records of Scotland, and the Northern Ireland Statistics and Research Agency, for their support and collaboration through the whole process; our force of 20,000 field staff who visited households and communal establishments across England and Wales and over 300 engagement staff who engaged with diverse communities and population groups; the local authorities, charities, and other stakeholders who worked closely with us to ensure that the census delivered for data users across sectors and across the country; and the staff in the ONS and the UK Statistics Authority, through whose hard work and professionalism we planned and delivered the enormous census operation from investigating user needs, through data-collection and processing, to publishing and disseminating the outputs.
Finally, the success of the census relies on members of the public across England and Wales. I would like to thank every one of them for taking the time to participate in Census 2021 and enabling us to produce the high-quality statistics that data users across the country need.
Professor Sir Ian Diamond
National Statistician (October 2019 to May 2025)
May 2025