Rich insights

We will release multivariate data from Census 2021, based on the usual resident population of England and Wales. These data will allow you to combine different variables and look at the relationships between the data, providing you with rich insights into the characteristics of the population of England and Wales.

New functionality

We are introducing new functionality for Census 2021 data that will allow you to make your own datasets, as well as view and download a set of ready-made datasets.

Multivariate datasets

We will publish ready-made multivariate datasets that each provide information about a particular set of variables for each area in England and Wales. These will provide full coverage of all geographic areas at the lowest geographic level for which the data are protected against the risk of disclosure, and acceptable to the Office for National Statistics (ONS).

For the usual resident population base, we generally plan to provide the ready-made multivariate datasets for all levels of the Output Area (OA) hierarchy. For the usual resident in households and usual resident in communal establishment population bases, we generally plan to provide the ready-made datasets down to Middle-layer Super Output Area (MSOA).

Before viewing and downloading these datasets, you will be able to:

  • select a level of geography, for example, local authorities

  • select whether you want data for all areas or filter for specific geographic areas, for example, Southampton and or Cardiff

  • filter for a specific category of the variables included in that dataset, for example, the population aged 16 to 24 years from the age variable

For the majority of datasets, there will be additional features that will allow you to:

  • amend the level of detail for each variable

  • add or remove variables

If you choose to change a dataset in this way, the system will then run dynamic disclosure control checks on your request. It will only provide the data for the geographic areas where the data are safe to share and meets ONS's criteria for publication.

There is a balance in that if you request data about more detailed classifications of variables, you are more likely to receive these for larger geographies than smaller geographies. Likewise, if you request data about very small geographies, you are more likely to receive these if you have requested less detail about the variables.

You are more likely to receive the data you request for particular areas, if your request includes:

  • combinations of up to three or four variables

  • less detailed classifications of variables

  • data for larger geographic areas

While the system will only provide the data for areas where it is safe to share, it will allow you to access more detailed characteristics about the makeup of areas that do support the data at lower geographies.

Keeping data safe

The new flexible functionality for Census 2021 is enabled through dynamic statistical disclosure control methodology that protects data confidentiality. Once you make a request for a dataset, the system will run automated disclosure checks in real time to determine if the requested data are safe to share. If the dataset passes our statistical disclosure checks, then you can view or download the data. If there are geographical areas that do not pass the disclosure checks, then you will be notified and only provided the requested data for the geographical areas that do pass the checks. At this point, you can choose to view the data that has been allowed or change their selections to make a different request.

Planned variables and classifications

Over summer 2021, we asked users for their views about which variables and classifications we planned to include in our Census 2021 datasets. This included the variables and classifications that we plan to publish in ready-made multivariate datasets and the list of variables and classifications you will be able to select from if you choose to change a dataset. You can download this information from our Draft proposals for outputs data content spreadsheet (xlsx, 609KB), on our consultation website. We are currently considering users' feedback and finalising our specifications for the Census 2021 multivariate datasets. We will publish our plans here, later in 2022.

Release plans

We plan to release multivariate data from Census 2021 during phase two of the Census 2021 outputs release schedule.

Where to find the data

We will publish Census 2021 multivariate datasets on our website, where you will be able to use the full flexibility on offer. We will also make the standard set of ready-made multivariate datasets available on the Nomis website.

More information

If you need more information about our plans for providing data from Census 2021, please contact us at census.outputs@ons.gov.uk.