General description

On 2 November 2022, the Office for National Statistics (ONS) published 'Demography and migration: Census 2021 in England and Wales', which helped form the Welsh Government's publication 'Demography and migration in Wales (Census 2021)'. This was an update to initial population and household estimates, and included an overview of the non-UK born population as well as characteristics of households and residents in Wales.

This table is based on Census table TS002 'Legal partnership status', which provides Census 2021 estimates that classify usual residents aged 16 years or older in Wales and England by their legal partnership status.

For Census 2021, the ONS made changes to the data (called statistical disclosure control) so that it is not possible to identify individuals. These changes included:
• Swapped records (targeted record swapping), for example, if a household was likely to be identified in datasets because it has unusual characteristics, they swapped the record with a similar one from a nearby small area. Very unusual households could be swapped with one in a nearby local authority.
• Added small changes to some counts (cell key perturbation), for example, change a count of four to a three or a five. This might make small differences between tables depending on how the data are broken down when perturbation is applied.

This causes small changes to cells but does not fundamentally impact the meaning of the data. Where tables are made in different ways, the changes applied will be different, leading to differences between totals and tables not ‘adding-up’ to their totals. To minimise this, the ONS recommends where possible using totals from tables with fewer cells, at higher geographies. For example, if you wanted population by age you should use data from TS007 and if you wanted population by sex you should use data from TS008.

More information about the processes used in statistical disclosure control will be provided in future publications.

A usual resident of Wales is anyone who was living or staying in Wales for 12 months or
longer on Census Day, 21 March 2021, or who had a permanent address in Wales and was staying outside Wales for less than 12 months.

Data collection and calculation

See weblinks

Frequency of publication

No longer updated

Data reference periods

21 March 2021

Users, uses and context

The data presented here are used by central government departments and local authorities for a range of purposes including for resource allocation, planning and monitoring of services, and as denominators for the calculation of various rates and indicators.

Rounding applied

To note the sums of local authorities may not add up the Wales figures due to the statistical disclosure methods applied to the data as described in the general description. Figures across different tables may also not match exactly due to statistical disclosure control methods applied to the data.

Statistical quality

Further information on the statistical disclosure controls (including perturbation) that have been applied to the data can be found here:
https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationestimates/methodologies/qualityandmethodologyinformationqmiforcensus2021#methods-used-to-produce-the-data

Title

Usual resident population in Wales by legal partnership status and area

Last update

November 2023 November 2023

Publishing organisation

Welsh Government

Source 1

2021 Census, Office for National statistics

Contact email

stats.popcensus@gov.wales

Designation

National Statistics

Geographical coverage

Local authorities

Languages covered

English and Welsh

Data licensing

You may use and re-use this data free of charge in any format or medium, under the terms of the Open Government License - see http://www.nationalarchives.gov.uk/doc/open-government-licence

Weblinks

https://www.gov.wales/demography-and-migration-wales-census-2021

https://www.ons.gov.uk/releases/demographyandmigrationcensus2021inenglandandwales

https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationestimates/methodologies/qualityandmethodologyinformationqmiforcensus2021#methods-used-to-produce-the-data

Keywords

2021 Census; Legal partnership status; Marital status; Population

Name

POPU2107