Students in migration estimates

Since the Government announced its ambition to reduce net migration “from the hundreds of thousands back down to the tens of thousands” in 2010, there has been a debate about whether students should count towards that target.

Those who argue that students should be removed from the net migration target point out that while students are around 25% of immigration, research suggests the public does not tend to think of students as migrants.

On the other hand, those who argue that students should be included in the net migration target point out that it only makes sense to discount student migration if students return to their home countries after completing their studies. But if everyone who migrated to the UK to study left the UK at the end of their studies, the contribution of these migrants to net migration would be zero over the long term.

It is also not clear what removing students from migration figures would mean in practice. Would international students no longer be counted as migrants in the production of official migration estimates? Or would student migrants simply be subtracted when measuring the Government’s progress against its net migration target?

Why are students included in migration estimates?

The official estimates of immigration, emigration and net migration, which you see reported in the news each quarter, aim to measure long-term international migration.

According to the United Nations definition, a long-term international migrant is someone who changes their country of usual residence for a period of at least one year. The UN definition is widely used in international migration statistics; for example all EU countries report migration statistics using this definition under an EU Regulation.

This definition means that international students who move to the UK for a year or more count as migrants in official migration estimates, while those who come to the UK for shorter periods (such as most of those studying on short-term study visas) do not.

Net migration is the difference between long-term migrants moving into and out of the country, so headline estimates of net migration include students living in the UK for a year or more.

Can students be removed from net migration estimates?

Strictly speaking, students can’t be removed from demographic estimates of net migration because the figure that results from excluding students is not net migration.

Net migration is an objective demographic quantity, which represents the part of population change that is due to migration. Broadly speaking, in any given period the change in the size of a population is equal to natural change (births minus deaths) plus net migration (immigration minus emigration).

So even if you aren’t trying to routinely measure net migration, if you know the population at two points in time, and you know the number of births and deaths between those dates, you can estimate net migration during that period as the difference between total population change and natural change.

The Office for National Statistics (ONS) uses estimates of net migration to produce annual estimates of the population between Census years. It would need to estimate net migration under the current definition for this purpose, irrespective of any changes to Government migration policy.

Can students be removed from the net migration target?

As the Government aims to reduce the overall level of net migration, international student migrants are included in the net migration target by default.

But there is a difference between removing international students from estimates of net migration and removing international students from the net migration target. The Government may aim to reduce any particular type of migration, or none at all.

However, there are technical difficulties in subtracting international student migration from the current migration estimates, which relate to how migration is measured.

In the UK, estimates of long-term international migration are based on the International Passenger Survey (IPS), which is a survey of people travelling through UK air, sea and rail ports.

Estimates of international student immigrants are based on survey respondents who are migrants and who say their main reason for migrating to the UK is to study. Estimates of emigrants who were international students in the UK are based on former immigrants who are leaving the UK and who say their original reason for immigration was to study.

Note that these figures refer to the migration of people who come to the UK to study: they do not include people migrating from the UK to study abroad if those people have never migrated before, or if they originally migrated to the UK for another reason.

The chart below shows estimates of immigration and emigration of people who migrate to the UK to study, which are available from 2012.

International Passanger Survey estimates of long-term international migration

This chart suggests that between 2012 and 2016 there were more than twice as many international student immigrants as emigrants who previously migrated to the UK to study. However, ONS now believes that the estimates of international student emigration shown in this chart may be too low.

Are estimates of international student migration reliable?

In April 2015 the Home Office introduced a new system of exit checks for people leaving the UK. In August 2017 the first statistics from these exit checks were published. ONS analysis of these statistics showed that departures of non-EU nationals holding student visas were higher than the International Passenger Survey implied. ONS said:

‘We now know that there is strong evidence to suggest that the International Passenger Survey (IPS) is likely to underestimate student emigration, therefore any attempt to estimate the contribution that students make to net migration is likely to be an overestimate.’

ONS said that while their research provides evidence that the IPS underestimates student emigration, it does not provide evidence to suggest these findings affect total net migration figures. If this analysis is correct, then removing net migration of international students from total net migration using the current figures would lead to an estimate of non-student net migration that is too low.

ONS is exploring what adjustments or other sources of migration statistics could be used to provide more reliable estimates of student migration. The issue of removing international students from the net migration target may therefore raise further questions about the way migration is measured in the UK.

Further information on this and other aspects of migration in the UK can be found in our briefing on Migration Statistics.

Picture Credit: NTU Graduation by Nottingham Trent University; Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0)