This article examines how patterns of long-term international migration vary at different times of the year.
The most common time for migration is during July to September (quarter three).
44% of immigrants to the UK arrive during quarter three, with the highest proportion (25%) during September. This is due to a peak in arrivals for study.
35% of emigrants left the UK during quarter three. This is driven by people emigrating for work related reasons.
There is significant interest in migration statistics, both nationally and internationally, and there is a need to understand how moves impact on society and the economy. Reporting generally focuses on year on year trends of long-term international migration, but there has been no published research into how migration patterns compare from one quarter of the year to another.
This summary uses International Passenger Survey (IPS) data to examine seasonal patterns of migration. Long-term International Migration (LTIM) is the most comprehensive measure of international migration and relates to those migrants changing their country of usual residence for 12 months or more so that the country of destination effectively becomes the country of usual residence. This is in line with the UN definition of a long-term migrant. The main component of LTIM is the IPS, which is a survey carried out at ports of entry across the UK. IPS data has been used in this article because estimates based only on the IPS allow a more detailed analysis of the characteristics of international migrants. The IPS data are uncalibrated1, which means that the estimates shown here may not match other published estimates.
The article looks at seasonal patterns of migration by different characteristics, such as age, sex, and reason for migration, to answer the following questions:
1. What are the seasonal patterns of long-term international migration?
2. Who migrates to and from the UK at different times of the year?
3. Why do people migrate to and from the UK at different times of the year?
4. Where do migrants arrive from or go to when they enter or leave the UK?
Quarterly Home Office visa data is analysed to see how seasonal patterns compare between this data source and the IPS. Allocations of National Insurance Numbers (NINo) to adult overseas nationals are also included to compare seasonal patterns with the IPS. These additional data sources allow a more complete picture of seasonal patterns of migration than would be available for the IPS alone.
Note: The IPS data used in this report has been split by quarter, and three years’ worth of quarterly data combined to create the estimates. This means that the data is un-calibrated i.e. the data has not been constrained to match the regional distribution of migrants. Therefore, this data may not match other published outputs of Long-Term International Migration. More information on calibration can be found in the report ‘The use of calibration in estimating international in-migration to UK Countries and the Regions of England’.
Over the last three years (2009 to 2011):
The most common time for migration is during July to September (quarter three).
44% of immigrants to the UK (704,000) arrive during quarter three, with the highest proportion (25%, or 406,000) during September. This is due to a peak in arrivals for study.
There is a peak in non-British migrants (in particular from non-EU countries) arriving during quarter three (45%, or 615,000). Of those non-British migrants arriving during quarter three, the majority are aged between 15 and 24 and coming to the UK to study.
India was the most common country of last residence in every quarter.
35% of emigrants left the UK during quarter three (347,000). This is driven by people emigrating for work related reasons.
British and non-British emigration follows similar patterns across each quarter. The most common reasons for emigration are work related (in particular with a definite job to go to) in all quarters.
Australia is the most common country of next residence in every quarter.
40% of visas are issued during quarter three (702,395), although a third of work visas (132,845) are issued during quarter two (April to June).
30% of National Insurance numbers (581,990) are allocated during quarter one (January to March) with 20%, 26%, and 24% in the following three quarters. There will be time lags in allocation of NINos following arrival.
Chart 1 shows the main findings of seasonal patterns of long-term immigration to the UK. Each segment represents the proportion of migrants arriving in the particular quarter.
Emigration from the UK does not show the same seasonal patterns as immigration. In each quarter, emigrants are most frequently single, male, aged 25 to 44, and leaving for work related reasons. In quarters one, three, and four, emigrants tend to be non-EU citizens, but in quarter two they are most frequently citizens of the EU.
Figure 1 shows estimates for long-term immigration, emigration, and net migration by month, covering the years 2009 to 2011.
As the IPS is a sample survey, years have been combined to give more reliable results than would be available from just one month in one year.
Over the last three years, monthly estimates show that 25% of migrants (406,000) moving to the UK for 12 months or more do so during September. Emigration does not show the same magnitude of increase in any particular month. 13% of emigrants (130,000) left the UK during August.
For the purposes of the remainder of this article, quarterly data has been produced, and the last three calendar years (2009, 2010, and 2011) have been combined. This quarterly data is more reliable for examining further detail than monthly data. The following table shows the months that each quarter contains, as well as how each quarter has been calculated from the three years of data.
|Quarter 1 (Q1 2009 + Q1 2010 + Q1 2011)||January, February, March|
|Quarter 2 (Q2 2009 + Q2 2010 + Q2 2011)||April, May, June|
|Quarter 3 (Q3 2009 + Q3 2010 + Q3 2011)||July, August, September|
|Quarter 4 (Q4 2009 + Q4 2010 + Q4 2011)||October, November, December|
Figure 2 shows that there is a higher level of both immigration and emigration during quarter three as opposed to migration during the other quarters. Between 2009 and 2011, 44% of long-term migrants (704,000) entered the UK during quarter three, compared to 17% of migrants (272,000) entering the UK during quarter two. Both quarter one (20% or 323,000) and quarter four (19% or 314,000) have similar levels of immigration.
In terms of emigration, 35% of migrants (347,000) left the UK during quarter three. This compares to 20% of migrants (197,000) leaving the UK during quarter one, similar to 21% (201,000) in quarter two.
Net migration for each quarter varies between 70,000 during quarter two to 357,000 during quarter three. In every quarter there are more people arriving in the UK than leaving.
60% of immigration (976,000 migrants) occurs during the “summer quarters” (quarter two and quarter three – covering the months April through to September). Similarly, 56% of emigration (548,000) occurs in these summer quarters.
This section compares seasonal patterns of migration by citizenship, age, sex, and marital status.
2a. Migration by citizenship
Figure 3 shows how British and non-British citizenship patterns compare in each quarter.
Seasonal migration of British citizens shows that quarter three is the peak quarter for both immigration and emigration, with 35% of British citizens (89,000) immigrating to the UK during quarter three, and 36% of British citizens (141,000) emigrating from the UK during this quarter. Please refer to Section 4 for details on where migrants are travelling to when they leave the UK for 12 months or more. This seasonal pattern is similar for non-British citizens, although the peak of immigrants during quarter three is much more pronounced, with 45% of non-British citizens (615,000) migrating to the UK during this quarter.
Figure 3 also shows that non-British citizenship outflow follows a similar seasonal pattern to British citizenship outflow.
Figure 4 shows quarterly migration patterns for EU (not including British citizens) and non-EU citizens.
IPS data can be compared with visa data from the Home Office and National Insurance number (NINo) data from the Department for Work and Pensions (DWP). There are some definitional differences between these sources, as described in the Migration Statistics Quarterly Report: Information for Users. Figure 5 shows the immigration estimates, entry clearance visas issued, and NINos allocated by percentage per quarter.
IPS data of course includes EU and British immigrants, whereas visa data is mostly restricted to those who require a visa to enter the UK. Visa data also includes individuals who do not have the intention of moving their residences to the UK for a year or more. However, quarterly patterns of immigration and visa data are very similar. This is likely to be due to non-EU students who are the largest group of immigrants that show in both data sources. NINo registration occurs once the individual has arrived in the UK, and are only required for those looking to work. Therefore, time lags will exist in the NINo data sources and are not required to be issued more than once for immigrants who return again. Bearing these factors in mind it is not surprising that quarterly patterns differ for NINos as compared with IPS and visa figures.
In terms of visas issued by world area, Figure 6 shows the number of visas issued (excluding visit and transit visas), by world area of citizenship.
The number of visas issued to Asian nationals is much higher than those from other world regions.
Please note: Europe in this context does not refer to the EU, but to everywhere in Europe that is not in the European Economic Area (EEA) or Switzerland. EEA nationals do not require a visa, however visa records suggest that small numbers apply and are issued with visas.
See the Glossary for discussion of world regions and differences between Home Office and DWP definitions.
Please refer to Section 4 for more detail on where migrants have come from and go to when they migrate to or from the UK.
Figure 7 shows data for NINos issued from DWP to adult overseas nationals in the UK.
30% of NINos (581,990) are issued during quarter one, with a third of these being issued to citizens from Asia and the Middle East. 20%, 26%, and 24% of NINos are issued in the following three quarters. Similarly, a third of NINos issued in quarter four are also issued to citizens from these countries. Figures for quarter two and three suggest that more NINos are allocated to migrants from the EU Accession countries (124,660 or 31% of allocations in quarter two, and 203,103 or 40% in quarter three) than to the other country groups. This may be due to seasonal workers coming to the UK for work over the summer months, although they are classed as long-term migrants who will remain in the UK for 12 months or more.
Figures show a peak in NINos issued for EU Accession countries in quarter three and high numbers issued in quarter one. For citizens from Asia and the Middle East the highest allocation numbers are in quarter four and quarter one. It is important to recognise that NINos will be issued some time after arrival (so for example, higher numbers in quarter four and quarter one would be consistent with high arrivals for study in quarter three as students may obtain NINos some time after arrival).
Please note: Caution should be taken in interpreting NINo trends based on raw quarterly data. The raw quarterly time series of NINo registrations to adult overseas nationals shows a number of peaks and troughs. The series is reflecting both seasonal effects in the registration of adult overseas nationals entering the UK and operational factors in recording a NINo on the DWP database.
2b. Migration by age, sex, and marital status
In terms of the characteristics of who is migrating each quarter, the following have been analysed further: age, sex, and marital status.
Figure 8 shows immigration estimates for each quarter by age group and sex.
Figure 9 shows emigration estimates for each quarter by age and sex.
More males immigrate to the UK than females during each quarter. The peak of immigration during quarter three (704,000) shows that 52% (363,000) are male, and 48% (341,000) are female. This equates to 41% of males and 46% of females migrating to the UK do so during this quarter.
More males emigrate during each quarter than females. During quarter three, where emigration is highest (347,000), 54% (187,000) are male and 46% (159,000) are female. More males and females emigrate during quarter three when compared to the other quarters, with 34% of males and 37% of females migrating from the UK during this quarter of the year.
Comparisons of migration by age group shows that, of immigrants entering during quarter three, half (51% or 358,000) are aged between 15 and 24, and 39% (275,000) are aged between 25 and 44. This could be related to student inflows (see Section 3 for more detail on why migrants arrive or leave the UK) as university students are aged 18 and above. These two age groups also make up 84% of emigrants during quarter three, with 93,000 aged between 15 and 24, and 200,000 aged between 25 and 44.
Slightly over half of immigration for those aged 15 to 24 occurs during quarter three (54%), and 37% of 25 to 44 year olds migrate during this same quarter. Estimates of migrants of retirement age arriving or leaving the UK for 12 months or more are low. 31% of this age group (9,000) migrate to the UK during quarter four.
Figure 8 also shows that for the age group 15 to 24 there were slightly more females than males arriving during quarter three (182,000 females compared to 176,000 males), which is different from the overall seasonal patterns by sex.
Seasonal emigration patterns by age group show that there are peaks for age groups 15 to 24 (40% of total emigration for this age group or 93,000) and 25 to 44 (34% of total emigration for this age group or 200,000) migrating during quarter three.
When comparing age group and sex, the estimates show that 32% of males aged 25 to 44 (111,000) emigrate during quarter three.
Tables 2 and 3 show migration estimates by marital status.
|Marital Status||Quarter 1||Quarter 2||Quarter 3||Quarter 4|
|Single, never married||206,000||154,000||529,000||190,000|
|Divorced / widowed||11,000||6,000||10,000||4,000|
|Marital Status||Quarter 1||Quarter 2||Quarter 3||Quarter 4|
|Single, never married||124,000||124,000||220,000||146,000|
|Divorced / widowed||6,000||4,000||7,000||7,000|
With regard to seasonal comparisons by marital status, nearly half (49% or 529,000) of single migrants travel to the UK during quarter three, whereas 33% of married (165,000), and 32% of divorced migrants (10,000) move to the UK during this quarter.
Please note: ‘Married’ includes civil partners, and ‘Divorced/Widowed’ includes civil partners whose partnership has been dissolved, and surviving civil partners.
Similar proportions of single (36% or 220,000) and married (35% or 120,000) people emigrate during quarter three.
Tables 4 and 5 show migration estimates by occupation prior to migration.
|Occupation Prior to Migration||Quarter 1||Quarter 2||Quarter 3||Quarter 4|
|Professional and Managerial||92,000||95,000||175,000||92,000|
|Manual and Clerical||90,000||65,000||107,000||73,000|
|Occupation Prior to Migration||Quarter 1||Quarter 2||Quarter 3||Quarter 4|
|Professional and Managerial||75,000||71,000||125,000||96,000|
|Manual and Clerical||64,000||73,000||95,000||73,000|
Occupation prior to migration shows that 39% of “Professional and Managerial” migrants (175,000) move to the UK during quarter three, and 34% (125,000) emigrate during quarter three. “Manual/clerical” occupations follow a similar pattern. Students migrating to the UK peak during quarter three with 57% (341,000) arriving to the UK at this time. Only 11% of students (63,000) migrate to the UK during quarter two.
Figures 10 and 11 show quarterly migration estimates for immigration and emigration by main reason for migration.
Since December 2009, rolling year data has shown that study is the main reason for migrating to the UK. However, when looking at quarterly patterns, it can be seen that when study estimates are compared to immigration for work related reasons, quarters one, two, and four see higher estimates for those arriving for work. The most common reason for immigration during quarter three is for study purposes. 59% of immigration (395,000) for study purposes occurs during quarter three. This is expected as many academic courses usually begin in September/October and explains why it is concentrated in quarter three. This compares to just 9% (59,000) during quarter two. However, when this is compared to emigration, work related reasons remain the most common reason for migrating in all quarters. 50% of those leaving for study purposes (31,000) do so during quarter three.
32% of those migrating to the UK for work related reasons (covering either a definite job or looking for work) migrated during quarter three. Similarly emigration estimates for work related reasons show that 35% (204,000) migrate during quarter three. 20% of those looking for work (42,000) arrived in quarter two, which compares to 31% (65,000) arriving in quarter three. Estimates for those with a definite job to go to show 24% (81,000) arrive in quarter two, and 33% (113,000) in quarter three.
Figure 12 shows visa data from the Home Office, split by reason, so that these can be compared with IPS reasons for migration.
702,395 visas (excluding visit and transit, but including student visitors) were issued during quarter three of years 2009 to 2011, accounting for 40% of the total number of visas issued during the three years of data. Visas issued for work purposes peak during quarter two, (132,845, or 29% of visas for work purposes are issued in this quarter), which may be related to people coming in for work over the summer months. Visas issued for study show a peak of 457,056 (57%) during quarter three. Using this evidence, along with IPS data on immigration for study, shows why there may be a trend of high migration during quarter three. Family related visas are evenly spread across each quarter of the year.
More work visas are issued in quarter two than any other type – in all other quarters study visas are the type most issued.
Investigating further to compare visa data on reason for migration data with IPS data for non-EU migrants, 70% of those arriving during quarter 3 (281,000) state study as their main reason for migrating to the UK. This is in line with visa data on study visas issued during this quarter. 26% of non-EU migrants (37,000) arriving during quarter two state work related reasons for coming to the UK. This increases to 33% (53,000) during quarter three. Therefore, visa data may suggest earlier arrival for the non-EU migrants to the UK, but this would be consistent with more preparatory steps taken by non-EU citizens prior to migrating to the UK.
Table 6 shows the top three countries of last and next residence split by quarter of arrival or departure, for combined years 2009 to 2011.
|Country of Last/Next Residence||Quarter 1||Quarter 2||Quarter 3||Quarter 4|
|Immigration||1. India (50,000)||1. India (32,000)||1. India (67,000)||1. India (53,000)|
|2. Poland (29,000)||2. Pakistan (22,000)||2. China (66,000)||2. Pakistan (21,000)|
|3. Pakistan (25,000)||3. Australia (21,000)||3. USA (40,000)||3. USA (15,000)|
|Emigration||1. Australia (31,000)||1. Australia (28,000)||1. Australia (43,000)||1. Australia (42,000)|
|2. USA (13,000)||2. USA (15,000)||2. USA (35,000)||2. Poland (16,000)|
|3. France (11,000)||3. Poland (14,000)||3. Poland (23,000)||3. India (15,000)|
India is the top country of last residence during every quarter, with 67,000 arriving during quarter three. Australia appears in the top three countries of last residence only once (in quarter two). China only appears in the top three countries of last residence during quarter three. By looking at main reason for migration during quarter two for those travelling from Australia, 48% (10,000) are aged 25 to 44 and of those, 5,000 are coming for work related reasons. Similarly, for those travelling from China during quarter three, 92% (61,000) are coming to the UK for study purposes.
Australia is the most common country of next residence in each quarter, and both quarter three and quarter four have similar estimates of 43,000 and 42,000 respectively. These migrants are mainly leaving the UK for work related reasons.
Tables 7 and 8 show migration estimates by intended length of stay.
|Intended Length of Stay||Quarter 1||Quarter 2||Quarter 3||Quarter 4|
|1 to 2 years||172,000||123,000||390,000||156,000|
|3 to 4 years||46,000||42,000||139,000||48,000|
|More than 4 years||81,000||91,000||149,000||89,000|
|Intended Length of Stay||Quarter 1||Quarter 2||Quarter 3||Quarter 4|
|1 to 2 years||37,000||40,000||69,000||42,000|
|3 to 4 years||18,000||12,000||30,000||15,000|
|More than 4 years||126,000||133,000||225,000||156,000|
When migrants arrive in the UK, they are asked how long they intend to stay in the UK. The most popular response in each quarter is ‘1 to 2 years’. Over half of those arriving during quarter three (the peak quarter for immigration) state ‘1 to 2 years’ (55% or 390,000). Similar numbers (139,000 and 149,000 respectively) state either ‘3 to 4 years’, or ‘More than 4 years’ when arriving during quarter three. The response ‘More than 4 years’ is stated more often than ‘3 to 4 years’ when comparing quarter on quarter.
Calibration is used to improve the regional distribution of immigrants. It is an estimation procedure which constrains sample-based estimates of auxiliary variables to known totals (or accurate estimates). For more information see ‘The use of calibration in estimating international in-migration to UK Countries and the Regions of England’.
Country of usual residence
The country in which a person has a place to live, where he or she normally spends the daily period of rest. Temporary travel abroad for purposes of recreation, holiday, visits to friends and relatives, business, medical treatment or religious pilgrimages does not change a person’s country of usual residence (UN based definition).
European Economic Area (EEA)
European Economic Area (EEA) consists of the EU Member States as constituted at the time as well as Iceland, Liechtenstein and Norway. Switzerland are not part of the EEA but have the same rights as those members of the EEA.
A person who leaves their country of usual residence to take up residence in another country for a period of at least 12 months.
An indication of the value of an unknown quantity based on observed data. The estimated number of migrants is calculated by weighting up the number of contacts collected by the IPS. Further information about the weightings used by the IPS can be obtained in the ‘International Passenger Survey (IPS) methodology’.
European Union (EU)
The EU consists of 27 countries: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Republic of Ireland, Romania, Slovakia, Slovenia, Spain, Sweden and the United Kingdom (P lease note: the United Kingdom is not included as part of the EU estimates mentioned throughout this report).
European Union (EU) Accession countries
The Accession countries are those that joined the EU in either 2004 or 2007. Ten joined in 2004 (the EU8, plus Cyprus and Malta), and two joined in 2007 (the EU2).
The EU2 (formerly known as the A2) are the two countries that joined the EU on 1 January 2007: Bulgaria and Romania. EU2 nationals currently have certain restrictions placed on them; in the first 12 months of stay, working Bulgarian and Romanian nationals are generally required to hold an accession worker card or apply for one of two lower-skilled quota schemes. Other Bulgarian and Romanian nationals can apply for a registration certificate, giving proof of a right to live in the UK.
The EU8 (formerly known as the A8) are the eight central and eastern European countries that joined the EU on 1 May 2004: Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Slovakia and Slovenia. The EU8 does not include the two other countries that joined on that date: Cyprus and Malta. EU8 nationals previously had restrictions on their rights to work and were required to register under the Worker Registration Scheme, but since 1 May 2011 EU8 nationals now have the same rights as other workers from the EU and EEA.
International Passenger Survey (IPS)
The International Passenger Survey (IPS) is a survey of a random sample of passengers entering and leaving the UK by air, sea or the Channel Tunnel. Over a quarter of a million face-to-face interviews are carried out each year. The IPS is carried out by ONS.
A person arriving or returning from abroad to take up residence in a country for a period of at least 12 months.
Long-term international migrant
Someone who moves to a country other than that of his or her usual residence for a period of at least a year so that the country of destination effectively becomes his or her new country of usual residence. From the perspective of the country of departure the person will be a long-term emigrant and from that country of arrival the person will be a long-term immigrant (based on UN definition).
Long-Term International Migration (LTIM) estimates are produced by combining migration data from the IPS, Home Office data on asylum seekers, migration to and from Northern Ireland (from the Northern Ireland Statistics and Research Agency) and adjustments for visitor switchers and migrant switchers. It is the most complete estimate of international migration to and from the UK.
The Home Office and DWP both use world region classifications. DWP have a breakdown of “Europe” into non-EU, EU accession countries and EU excluding non-accession countries. The Home Office only have a combined “Europe” category that in practice virtually consitsts of European states, including Turkey, that excluding the European Economic Area (EEA) and Swiss nationals (EEA and Swiss nationality generally do not require visas to enter the UK). The DWP classification also combines the Home Office Asia and Middle East categories. The Home Office Europe” classification, unlike the DWP classification, also includes the former Soviet Central Asian republics and has some other minor definitional differences. The categories “Oceania” and “Australasia and Oceania” are the same, again apart from minor definitional differences.
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