1.1 How many migrants are living in each local authority?
As you scroll through this section you will find two charts. Figure 1 deals with the share of migrants in local areas across Great Britain. Figure 2 shows the size of the EU- and non-EU born populations in those areas. Type into the search box or click or tap the chart elements to bring up information about a specific location.
The most up-to-date source of information on the number of migrants residing in local authorities is usually the Office for National Statistics’ (ONS) Population of the UK by Country of Birth and Nationality dataset for England and Wales; similar data for local authorities in Scotland are available through National Records Scotland (NRS). These data provide local-level estimates by both country of birth and nationality, and break the migrant population down by region of origin (e.g. EU-14, EU-8, etc.). The available estimates for Northern Ireland cover the whole of Northern Ireland rather than local authorities. They are included in the ONS dataset and accessible from the Northern Ireland Statistics and Research Agency (NISRA). The ONS Local Area Migration Indicators suite and the Scottish Local Area Migration data bring together the available local-level estimates by country of birth and nationality for all parts of the UK.
Figure 1 shows how the foreign-born share of the population varied across local authorities in the UK in 2018 by presenting: (1) overall estimates of the foreign-born population across local authorities; and (2) estimates of the share of foreign-born in the LA population.
The Annual Population Survey (APS), which is used for the ONS publication, Population of the UK by country of birth and nationality, is a survey of households in the UK. The National Records of Scotland (NRS) also uses the APS to provide estimates specific to Scottish local authorities, in a similar publication called Population by Country of Birth and Nationality. APS estimates are not available for local authorities in Northern Ireland. The APS does not cover all migrants: estimates exclude people living in communal establishments – e.g. hotels, caravan parks and other communal establishments – and may undercount subgroups of people with lower-than-average response rates to the survey, as well as recently arrived, or short-term migrants. Response rates have declined over the past 20 years.
Margins of error in survey data
Caution must be used when examining estimates of small groups because of margins of error. Estimates represent what is considered to be the most likely figure, but the true number could be higher or lower. APS and IPS data are reported with 95% confidence intervals which indicate the margins of error. For example, the estimated non-UK born population residing in the UK in 2018 was 9,342,000, with a confidence interval of +/- 146,000. One effect of this is that it may not be sensible to make too much of the difference between two estimates – small differences may result from statistical noise rather than real changes in the population. Users should look at the trend over several years as in some cases the apparent year on year change may be misleading.
In some local areas, confidence intervals are quite wide relative to estimates of the population of interest. For example, the estimated non-EU born population living in Sunderland was 8,000 in 2017 and 2018, with a confidence interval of +/-4,000. The corresponding estimate for the year 2016 was 6,000. In other words, the data do not show with certainty that the non-EU born population of Sunderland changed between 2016 and 2018.
Figure 2 shows the ONS estimates for the EU and non-EU born populations since 2004. Changes in the foreign-born population in specific local authorities from one year to the next should be treated with caution, however, because local-level estimates often come with substantial margins of error. It is therefore better to look at long-term trends rather than year-on-year changes.
The main ONS dataset providing these data also contains the same local-area information by nationality rather than country of birth (ONS table 2.1). It is important to note when using nationality data that some groups of migrants are more likely to become UK citizens than others (specifically, non-EU citizens are more likely to naturalise than EU citizens) and will therefore not be counted. There are also estimates for the working age (16 to 64 year old) population (ONS tables 1.2 and 2.2).
ONS also provides a dataset broken down by individual nationalities and countries of birth, although in most cases the numbers for individual countries of origin are either too small to estimate or come with large margins of error relative to the estimate itself.
The Annual Population Survey (APS), which is used for the ONS publication, Population of the UK by country of birth and nationality, is a survey of households in the UK. The National Records of Scotland (NRS) also uses the APS to provide estimates specific to Scottish local authorities, in a similar publication called Population by Country of Birth and Nationality. APS estimates are not available for local authorities in Northern Ireland. The APS does not cover all migrants: estimates exclude people living in communal establishments – e.g. hotels, caravan parks and other communal establishments – and may undercount subgroups of people with lower-than-average response rates to the survey, as well as recently arrived, or short-term migrants. Response rates have declined over the past 20 years.
Margins of error in survey data
Caution must be used when examining estimates of small groups because of margins of error. Estimates represent what is considered to be the most likely figure, but the true number could be higher or lower. APS and IPS data are reported with 95% confidence intervals which indicate the margins of error. For example, the estimated non-UK born population residing in the UK in 2018 was 9,342,000, with a confidence interval of +/- 146,000. One effect of this is that it may not be sensible to make too much of the difference between two estimates – small differences may result from statistical noise rather than real changes in the population. Users should look at the trend over several years as in some cases the apparent year on year change may be misleading.
In some local areas, confidence intervals are quite wide relative to estimates of the population of interest. For example, the estimated non-EU born population living in Sunderland was 8,000 in 2017 and 2018, with a confidence interval of +/-4,000. The corresponding estimate for the year 2016 was 6,000. In other words, the data do not show with certainty that the non-EU born population of Sunderland changed between 2016 and 2018.
