Migration Statistics Quarterly Report: November 2017

A summary of the latest official long-term international migration statistics for the UK for the year ending June 2017 published by Office for National Statistics (ONS). The report also includes data from the Home Office and the Department for Work and Pensions (DWP) for the year ending September 2017.

Nid hwn yw'r datganiad diweddaraf. Gweld y datganiad diweddaraf

16 July 2018 09:30

A correction has been made to the data contained within the Migration Statistics Quarterly Report: November 2017. During an assurance process of the International Passenger Survey data, a review of the weighting process identified a small error in the weights given to some shifts for the year ending June 2017 data.

The corrected data for year ending June 2017 can be found in our “Provisional Long-Term International Migration estimates” tables.

The data in the original release has not been corrected due to the next quarterly release, for the year ending December 2017 being published on 16 July 2018 which includes all the corrected data.

We apologise for any inconvenience.

Gweld y fersiwn wedi'i disodli
This is an accredited National Statistic. Click for information about types of official statistics.

Cyswllt:
Email Nicola White

Dyddiad y datganiad:
30 November 2017

Cyhoeddiad nesaf:
22 February 2018

1. Main points

Immigration to the UK continues to be higher than emigration, meaning that more people are coming to live in the UK than are leaving.

Net migration, the difference between the number of people coming to live in the UK and the number of people leaving to live elsewhere, fell to 230,000 in the year ending June 2017. This was down from the recent peak seen in the year ending June 2016 and is now at a similar level to 2014. EU net migration accounts for over three-quarters of the fall in net migration.

Over the longer term, varying levels of net migration are not unusual and we have seen net migration rise and fall between 140,000 and 336,000 over the last 20 years.

While immigration continues to be higher than emigration, the total number of people immigrating has fallen. At the same time, the number of EU citizens emigrating has increased.

The number of people moving to the UK to take up a “definite job” has remained stable, however, fewer people were coming to the UK “looking for work”.

This quarter we also release an article to explain Migration since the Brexit vote: what’s changed in six charts.

Nôl i'r tabl cynnwys

2. Latest figures

  • Net long-term international migration was estimated to be +230,000 in year ending (YE) June 2017, down 106,000 since YE June 2016 from a high of +336,000; immigration was 572,000, down 80,000 (both statistically significant), and emigration was 342,000, up 26,000 (not statistically significant).

  • Over three-quarters of the decrease in net migration can be accounted for by EU citizens (down 82,000 to +107,000 – a statistically significant decrease).

  • More people are arriving in the UK than leaving, meaning that net migration is above zero; adding to the non-UK population and so the non-UK workforce.

  • The 80,000 decrease in immigration included falls for both EU citizens (down 54,000 to 230,000) and non-EU citizens (down 28,000 to 263,000); EU emigration increased by 28,000 to 123,000 in YE June 2017 (all statistically significant changes).

  • Long-term immigration to work decreased by 51,000 to 261,000, in YE June 2017, those immigrating with a “definite job” remained stable (187,000); while the decrease was driven by fewer people coming to the UK “looking for work” (down 56,000 to 74,000), driven by EU citizens (down 47,000) (both statistically significant changes).

  • Long-term immigration to study (141,000) for all nationalities saw a decrease of 23,000 (not statistically significant) from YE June 2016; most were non-EU citizens (95,000 – down 18,000); however, the comparable number of study visas issued rose by 5% to 143,735.

  • In YE September 2017, a total of 15,618 people were granted asylum, resettlement or an alternative form of protection; this is similar to the previous year’s total of 15,433.

  • This quarter annual data tables including more detailed characteristics of migrant flows for 2016 final estimates are published; for example, in 2016, the largest inflow of immigrants to the UK was from Romania (50,000), the largest outflow of British citizens emigrating was to Australia (25,000) and of non-British citizens was to Poland (20,000).

Nôl i'r tabl cynnwys

3. Statistician’s comment

“Overall, more people are still coming to live in the UK than are leaving and therefore net migration is adding to the UK population.

“The first full year of data since the EU referendum vote in 2016 shows a decrease in the number of people coming to live in the UK and an increase in the number leaving, resulting in a fall in net migration of 106,000. Over three-quarters of the fall in net migration was accounted for by EU citizens.

“The decline follows historically high levels of immigration and it is too early to say whether this represents a long-term trend.

“The number of people immigrating for a definite job has remained stable but there has been a 43% decrease in the number of people immigrating to look for work over the last year, especially for EU citizens.

“These changes suggest that Brexit is likely to be a factor in people's decision to move to or from the UK – but decisions to migrate are complex and other factors are also going to be influencing the figures.”

Nicola White, Head of International Migration Statistics, Office for National Statistics.

Follow ONS Director of Migration Statistics @JayLindop_ONS

Nôl i'r tabl cynnwys

4. International migration over the last 10 years

The most recent estimates show that net migration has fallen to +230,000. Over the longer term, varying levels of net migration are not unusual and we have seen net migration rise and fall between +140,000 and +336,000 over the last 20 years (Figure 1 and Migration timeline).

The fall in net migration in year ending (YE) June 2017 comes after a short period of high net migration and is back at the level seen in YE March 2014. The most recent low was +154,000 in YE September 2012.

Section 7 provides further historical trends from 1964 for long-term international migration to and from the UK and shows that net migration has been positive since 1994.

The ONS international migration and the Home Office migration research and analysis pages provide links to further publications including a new article on Migration since the Brexit vote.

Nôl i'r tabl cynnwys

5. Things you need to know about this release

The reporting period for the International Passenger Survey (IPS) and so Long-Term International Migration (LTIM) data in this release is year ending (YE) June 2017 and therefore is a full year of data following the EU referendum. Entry clearance visa, National Insurance number (NINo) and labour market data are available to the end of September 2017.

Office for National Statistics (ONS) migration statistics use the UN recommended definition of a long-term international migrant: “A person who moves to a country other than that of his or her usual residence for a period of at least a year (12 months), so that the country of destination effectively becomes his or her new country of usual residence.”

By its nature it is not possible to quantify accurately the number of people who are in the country illegally. For this reason, ONS does not produce estimates on the size of the illegal migrant population. However, while our data do not identify illegal migrants separately, many will be included in our data. Defining and measuring “illegal migration” will be considered in our development plans.

The Long-Term International Migration (LTIM) estimates methodology describes how data from the IPS and other sources are used to create LTIM estimates. Some estimates are only available based solely on IPS data. Differences between ONS, Home Office, Department for Work and Pensions (DWP) and other sources are described in Comparing sources of international migration statistics.

Full details of definitions and glossary terms can be found in the Migration statistics first time user guide, glossary and list of products.

Nôl i'r tabl cynnwys

6. Net migration falls to +230,000

The Long-Term International Migration (LTIM) net migration estimate (the difference between immigration and emigration) for the year ending (YE) June 2017 was +230,000, compared with +336,000 in YE June 2016 (Table 1 and Figure 1). This 106,000 difference was statistically significant and was the largest annual decrease recorded, in part, due to the high seen in YE June 2016. Net migration is the lowest recorded estimate since YE December 2013 and similar to the level seen in 2014.

Net migration, which contributes to the total population of the UK, remains above zero at +230,000, meaning that more people are arriving in the UK than leaving. This means that migration is adding to the UK population each year.

In YE June 2017, the 80,000 decrease in immigration and the 26,000 increase in emigration combines to produce the net migration decrease of 106,000 compared with the previous year (emigration increase was not statistically significant as shown in Table 1).

EU international migration accounts for over three-quarters of the net migration change

Over three-quarters of the decrease in net migration to YE June 2017 is accounted for by a statistically significant decrease of 82,000 for EU citizens, falling from the recent high recorded in YE June 2016 (Table 2 and Figure 2). EU net migration is the lowest since YE June 2013.

The change in EU net migration is accounted for by decreases for both EU15 (down 29,000) and EU8 citizens (down 34,000) (both statistically significant), and a decrease of 21,000 for EU2 citizens (not statistically significant). Given the wider economic changes across the EU, a decrease in EU net migration might be expected.

Net migration for EU8 citizens is small, with similar numbers arriving as leaving. EU15 citizens still make up the majority of the EU migrating population but this is at its lowest level since YE June 2013 (Figure 2).

Non-EU net migration is also down (although the change over the last year is not statistically significant) and British net migration has remained the same.

Large immigration fall driven by both EU and non-EU citizens

Immigration remains much higher than emigration accounting for the positive net migration over the last 20 years. In the YE June 2017 there was a statistically significant decrease of 80,000 for immigration compared with YE June 2016. This decrease was driven by falls for both EU citizens (down 54,000 to 230,000) and non-EU citizens (down 28,000 to 263,000) (Figure 3 and Table 3).

The total immigration estimate of 652,000 in YE June 2016 was the highest immigration estimate recorded, while the latest figure of 572,000 is the lowest estimate recorded since YE March 2014, producing the large fall reported this quarter (Figure 3).

The emigration estimate of 342,000 is similar to YE March 2017. The highest estimate recorded for emigration (427,000) was in YE December 2008, following the 2008 recession.

Lower level of EU net migration is driven by a fall in immigration and a rise in emigration

Both EU immigration and EU emigration saw statistically significant changes in the YE June 2017 as fewer EU citizens moved to the UK and more left, producing the large net migration change (Table 3).

The large immigration fall (54,000) for EU citizens down to 230,000 was from a peak in YE June 2016 when EU immigration was at its highest estimate recorded (284,000). The majority of the reduction in immigration relates to fewer EU citizens coming to the UK to look for work (a 47,000 decrease).

EU8 citizens saw a statistically significant decrease of 24,000 in immigration to 49,000. This fall continues a decline in EU8 immigration seen since the 2008 recession, following the peak in the immediate period following these countries’ accession to the EU in 2004.

EU15 immigration is still the largest group in the EU but saw a decrease to the lowest level in three years (down to 119,000). EU2 saw a more modest decrease, to 58,000, similar to the change reported last quarter while still outnumbering EU8 immigration (Table 3, neither change was statistically significant).

The overall rise in EU emigration to 123,000 in YE June 2017 was the highest level since YE December 2008 when EU8 emigration was at its peak (134,000) following the 2008 recession. The rise is accounted for by increases for EU15, EU8 and EU2 but none of the individual EU group changes were statistically significant (Table 3). Combined with immigration these emigration increases are reflected in the statistically significant net migration decreases for EU15 and EU8 citizens (Table 2).

Emigration from the UK for British citizens was stable (128,000) and is now similar to the number of EU citizens emigrating (123,000) (Figure 3).

More detailed Long-Term International Migration (LTIM) estimates of immigration, emigration and net migration by citizenship over time, along with confidence intervals around all the estimates can be found in Table 1, Chart 1TS and Chart 1 Net in the accompanying datasets.

Nôl i'r tabl cynnwys

7. Why do people move to and from the UK?

International Passenger Survey (IPS) data show that the reason for immigration varies by nationality group with, for example, EU immigrants accounting for the majority (58%) of people arriving for work. Differences in reason for immigration are likely to reflect the differing rights of EU and non-EU citizens to migrate to the UK, as well as the effect of government policies and other factors (such as economic conditions in origin countries).

People moving to the UK for work falls by 51,000

Long-Term International Migration (LTIM) estimated there was a 51,000 decrease in people immigrating for work to 261,000 in the year ending (YE) June 2017 compared with the YE June 2016, which was the highest estimate recorded (312,000). This difference was statistically significant.

The number of people immigrating for a definite job has remained stable (187,000) over recent years. Fewer people arrived to the UK looking for work (down 56,000 to 74,000 – a statistically significant decrease), which has driven the overall decrease in work. Of all people moving to the UK for work, 28% were looking for work in YE June 2017 compared with 42% in YE June 2016.

International Passenger Survey (IPS) data show that the decrease in people arriving looking for work is accounted for by EU citizens, down 47,000 to 35,000 (statistically significant). Of EU workers, 24% were looking for work in YE June 2017 compared with 43% in YE June 2016.

In YE June 2017, EU15 immigrants were less likely to move looking for work than they were a year ago (down 22,000 over the year to 12,000), as were EU8 immigrants (down 17,000 to 10,000) (both statically significant changes) (Figure 5).

The estimate of non-EU immigrants arriving to work was 65,000 in YE June 2017. Of these, 17,000 (26%) arrived looking for work, which is likely to be accounted for by people granted visas under the Youth Mobility Scheme.

The majority of non-EU citizens arriving for work will be coming to take skilled jobs. Home Office visa statistics show that the number of visas granted for longer than 12 months to skilled workers (and their dependents) rose by 2,767 (4%) to 71,607 for YE September 2017. More details of nationality and sector of work are provided in the Home Office Immigration Statistics release.

Further work-related immigration data

In addition to the Long-Term International Migration (LTIM) and International Passenger Survey (IPS) estimates, further detail on work-related immigration is available from a number of sources including:

  • Home Office visa statistics

  • Department for Work and Pensions (DWP) National Insurance number (NINo) allocations

  • Office for National Statistics (ONS) estimates on UK and non-UK people in the labour market

Differences between these sources are described in Comparing sources of international migration statistics.

Work-related visas (non-European Economic Area (EEA) nationals)

In the year ending (YE) September 2017, there were 93,700 sponsored skilled work (Tier 2) visas granted, a similar level to the previous year. Tier 5 youth mobility and temporary visas were also broadly stable (1% lower) at 41,652. In the YE September 2017, in all work categories there were 164,383 work-related visas (including dependants) granted, around the same level as in the YE September 2016 (Table 4).

Indian nationals accounted for 57% of total skilled work visas granted (53,009 of 93,700); and the information technology sector sponsored 40% of skilled work visa applications.

More detailed statistics by citizenship, industry sector and the underlying data can be found in the Home Office Immigration Statistics release. Due to differing definitions these visa data are not directly comparable with long-term immigration estimates from the International Passenger Survey, as explained in the comparing sources article.

How many adult overseas nationals register for a National Insurance number (NINo)?

National Insurance number (NINo) registrations and IPS estimates should not be directly compared. NINo figures include short-term migrants and the figures are based on the recorded registration date on the National Insurance Recording and Pay As You Earn System (NPS) (after the NINo application process has been completed). More detailed information on these differences is discussed in the publication from 12 May 2016.

In the year ending September 2017 (Figure 6):

  • there were 741,000 NINo registrations overall, a decrease of 10% on the previous year

  • there were 548,000 NINo registrations from EU nationals, a decrease of 13% on the previous year

  • within the EU, registrations to: EU15 fell by 10% to 208,000, EU8 fell by 24% to 126,000 and EU2 fell by 7% to 211,000

  • there were 192,000 NINo registrations from non-EU nationals, a decrease of 2% on the previous year

As with the Long-Term International Migration (LTIM) estimates, NINo registration numbers reflect the rise in EU immigration between 2012 and 2015. The sharp rise in registrations to EU2 nationals in 2014 to some extent mirrors the long-term migration trend, in particular since the lifting of the transitional controls in 2014.

Following a recent peak in 2015, the total number of NINo registrations have been falling – this is driven mainly by a fall from the EU while registrations from outside the EU have remained broadly level.

The Department for Work and Pensions (DWP) statistical first release on NINo registrations and the summary tables provide more detail. Further information including detail on data sources, uses and limitations of the series is provided in the background information.

NINo allocations to adult overseas nationals and nationality at point of NINo registration of DWP working age benefit recipients (NINo benefit claimants) are no longer badged as National Statistics. The statistics continue to be published as official statistics following Office for Statistics Regulation reassessment of the statistics. The full assessment can be found on the UK Statistics Authority website in a report on the reassessment of the NINo statistics.

Overseas nationals in the UK labour market

Labour market statistics are estimates of the resident population of people working in the UK and measure the net change in employment, unemployment and inactivity. They are not designed to provide a measure of migration flows.

These data include people resident in the UK for many years as well as more recent arrivals. The best measure of total migration flows into and out of the UK is the International Passenger Survey (IPS). As a result, changes in the labour market stock cannot be directly compared with long-term net migration.

Estimates of labour market activity by nationality and country of birth are published quarterly. These statistics are derived from the Labour Force Survey up to the latest period, that is, July to September 2017.

The latest estimates show:

  • there were 2.38 million EU nationals working in the UK, 112,000 more than a year earlier

  • there were 1.21 million non-EU nationals working in the UK, 23,000 fewer than a year earlier

  • the employment rate (the proportion of people aged 16 to 64 years who were in work) was 81.6% for EU nationals, higher than that for UK nationals (75.3%) and higher than that for non-EU nationals (63.6%)

Changes in the estimated numbers in employment, unemployment and economic inactivity are not the same or directly comparable with the migration flows. The flows show that more people are arriving in the UK than leaving meaning that net migration is above zero. This means that migration is adding to the non-UK population, which is reflected in the increasing numbers of non-UK workers. The labour market estimates also include non-UK nationals who have lived in the UK for many years and who are moving in and out of employment or between the labour market statuses, which could also contribute to the increase.

An in-depth analysis of the labour market characteristics of UK, EU and non-EU nationals in the UK in 2016 was published in April 2017.

Study was the second most common reason for immigration

Long-Term International Migration (LTIM) estimates show that immigration for study (141,000) was the second most common reason for migration in year ending (YE) June 2017. Immigration to study saw a decrease of 23,000 compared with the previous year but the change was not statistically significant (see LTIM data in Table 2, Chart 2a and 2b in the accompanying datasets).

International Passenger Survey (IPS) data show that, of those whose main reason for long-term immigration was study, the majority (95,000 or 70%) were non-EU citizens (Figure 4) – a decrease of 18,000 on the previous year (not statistically significant). However, the comparable number of visas issued over the year to YE June 2017 to non-EU students for 12 months or more reported by the Home Office rose by 5% to 143,735.

Student immigration follows a seasonal pattern, with the majority of international students arriving between July and September. As such, annual figures typically change most in the YE September period. Therefore, the decrease from YE June 2016 to YE June 2017 is to be expected following similar figures in the last three quarters.

As noted, there is a difference between the long-term IPS estimates for immigration to study and the numbers of long-term student visas issued by the Home Office. There are a range of potential reasons why the data sources might differ, such as: timing, stated intentions and length of stay, sampling variability in the survey and if a visa was used or not, as discussed in the student section in the Migration Statistics Quarterly Report: February 2017 statistical bulletin.

The latest research on understanding international student migration was published in August 2017. Differences are explained further in Comparing sources of international migration statistics.

Home Office visa data provide additional detail for non-EU migrant students. The most recent data for YE September 2017 show the total sponsored visa applications to study (for all visa lengths) from non-EU nationals (main applicants only) rose by 6% to 212,381.

This included changes in visa applications to study as follows:

  • a rise for higher education (to 177,961, up 6%); within this total, applications to Russell Group universities rose by 9%

  • an increase for independent schools (to 13,787, up 3%) and English language schools (to 3,755, up 34%)

  • a fall for the further education sector (to 14,278, down 4%)

More than one-third (39%) of non-EU study visas were granted to Chinese students (88,258, up by 11,697 or 15% compared with a year earlier).

More detailed estimates over time can be found for LTIM in Table 2 and for IPS in Table 3 in the accompanying datasets. More detailed statistics and underlying data on visas for study reasons can be found in the Home Office Immigration Statistics release.

Most people moved abroad for work-related reasons

Long-Term International Migration (LTIM) estimated that over half of all emigrants (183,000) moved abroad for work in year ending (YE) June 2017. EU emigrants moving abroad for work reasons increased by 15,000 (statistically significant) to 57,000 in YE June 2017.

Similar to immigration, people were more likely to move abroad with a definite job (122,000) than to be looking for work (61,000) (Figure 7). People moving for a definite job saw an increase of 18,000 and this was accounted for by an increase of non-British citizens (statistically significant increases).

More detailed LTIM and IPS estimates over time can be found in Tables 2 and 3 in the accompanying datasets.

Other reasons for international migration

Long-Term International Migration (LTIM) estimates for year ending (YE) June 2017 for other reasons include:

  • to accompany or join others (80,000 immigrants; 29,000 emigrants)

  • other reasons (64,000 immigrants; 31,000 emigrants)

  • no stated reason (27,000 immigrants; 75,000 emigrants)

International Passenger Survey (IPS) estimates showed that 43,000 EU citizens stated they were emigrating to return home to live in YE June 2017, in addition to those returning home to work or for other reasons, a statistically significant increase of 15,000 compared with the previous year (Figure 7).

More detailed estimates over time can be found for LTIM in Table 2 and for IPS in Table 3 in the accompanying datasets. More detailed statistics and underlying data on visas for family reasons can be found in the Home Office Immigration Statistics release.

How many people are granted asylum in the UK?

In the year ending September 2017, there were 15,618 grants of asylum, alternative forms of protection and resettlement. This comprised of:

  • 8,147 grants of asylum

  • 1,123 grants of alternative form of protection (including dependents) to main applicants and their dependants

  • 6,348 people provided with protection and support under a resettlement scheme

A total of 9,394 people have been granted humanitarian protection under the Vulnerable Persons Relocation Scheme (VPRS) since the scheme began, and in the year ending September 2017, 4,980 people were resettled under the VPRS across 91 different local authorities.

More detailed statistics and underlying data on asylum and protection can be found in the Home Office Immigration Statistics release.

Nôl i'r tabl cynnwys

8. Further characteristics of long-term international migrants

In this release we publish our final annual Long-Term International Migration (LTIM), International Passenger Survey (IPS) and methodology tables for 2016. Most of the tables contain information on migration by a number of other variables besides citizenship and reason for migration, for example, by age, sex, country of birth, occupation or country of next or last residence. The series also includes historical trends from 1964 for long-term international migration to and from the UK by British citizens, EU citizens (further split by EU15, EU8 and EU2 citizens) and non-EU citizens, with the underlying data published in new Table 2.00.

Figure 8: Long-Term International Migration to and from the UK, 1964 to 2016

Embed code

Some findings from the updated tables for 2016 include:

  • net migration to the UK has been continually positive since 1994 with more people moving to the UK than leaving every year since (Table 2.00)

  • of the regions within England, the largest number of immigrants moved to London (156,000) and the lowest number of immigrants moved to the North East (22,000) (Table 2.06)

  • emigration for 2016 increased compared with 2015, particularly for men aged 25 to 44 years, while immigration for EU8 women decreased (Table 2.07 and Table 3.05)

  • EU citizens returning to EU countries increased compared with 2015, particularly for EU8 citizens to EU8 countries (Table 3.01)

  • both professional and managerial, and clerical and manual occupations prior to emigration saw increases compared with 2015 (Table 3.13)

  • emigrants are much more likely to have been in the UK for one to four years compared with 2015; accounted for by EU citizens across all groups (Table 3.15)

  • the largest inflow of immigrants to the UK was from Romania (50,000) followed by China, India, France and Poland (Table 3.20a)

  • the largest outflow of emigrants from the UK was to Australia (31,000) followed by the US, Spain, Poland and France (Table 3.20a)

You can find a detailed overview of the newly updated final annual 2016 tables in the LTIM 1-Series and 2-Series, and IPS 3-Series and 4-Series tables in the Table of Contents alongside other regular ONS migration releases.

Nôl i'r tabl cynnwys

10. What has changed in this publication?

Data tables based upon the old country groupings used before the Consultation on Country Groupings in International Migration Statistics conducted in 2014 have been removed from the published accompanying datasets. Estimates using some of the old country groupings (Old and New Commonwealth and British excluding British Overseas) are still available in the International Passenger Survey (IPS) 4-series tables in the annual final data tables published each year in November.

From 2016 onwards, all the country groupings currently used in Long-Term International Migration (LTIM) 2-Series tables, IPS 3-Series and 4-Series tables, LTIM and IPS quarterly provisional tables, Short-Term International Migration (STIM) tables and Annual Population Survey (APS) population tables are listed in the Table of Contents.

Following the Consultation on International Migration Statistics Outputs published in 2017, a review of the annual final tables was completed. Tables comparing the old and new country groups, tables which were poorly accessed or whose data are available in more detailed tables have been discontinued.

All annual data tables and flow tables covering the period up to 2015 using the old groupings are still available but some will be marked as “discontinued” with no data available from 2016 onwards. In line with current practice, tables may be available on request, subject to ONS charging policy, through MigStatsUnit@ons.gov.uk.

Nôl i'r tabl cynnwys

11. Quality and methodology

The Long-Term International Migration Quality and Methodology Information report contains important information on:

  • the strengths and limitations of the data and how it compares with related data

  • users and uses of the data

  • how the output was created

  • the quality of the output including the accuracy of the data

For more detailed information on how our migration statistics are used, along with information on their strengths and limitations, please see Long-Term International Migration estimates methodology, International Passenger Survey quality information in relation to migration flows and International migration methodology

A note on accuracy of the long-term migration estimates

Surveys gather information from a sample of people from a population. Using the International Passenger Survey (IPS) as an example, the population is passengers travelling through the main entry and exit points from the UK including airports, seaports and the Channel Tunnel. The estimates produced are based on only one of a number of possible samples that could have been drawn at a given point in time. Each of these possible samples would produce an estimated number of migrants. These may be different from the true value that would have been obtained if it were possible to ask everyone passing through about their migration intentions. This is known as sampling variability.

A confidence interval is a measure of the uncertainty around the estimate. Confidence intervals are reported in the accompanying datasets. Users are advised to be cautious when making inferences from estimates with relatively large confidence intervals. For immigration and emigration estimates where the lower confidence interval is below zero, users should assume the estimate is above zero. Estimates from a survey could change from one period to the next simply due to sampling variability. In other words, the change may be due to which individuals were selected to answer the survey and may not represent any real-world change in migration patterns.

For further information on confidence intervals, the accuracy of these statistics, comparing different data sources, and the difference between provisional and final figures, please see the Migration Statistics Quarterly Report – information for users and the Long-Term International Migration – frequently asked questions and background notes.

Revisions to net migration estimates in light of the 2011 Census

In April 2014, we published a report examining the quality of international migration statistics between 2001 and 2011, using the results of the 2011 Census. As a result we published a revised series of net migration estimates for the UK. Published tables have been updated to include the revised estimates. The report, a summary and guidance on how to use these revised figures are available. No revisions were made to separate immigration and emigration estimates at the time the net migration estimates were revised.

Nôl i'r tabl cynnwys