Today’s migration statistics show a marked decline in net migration to the UK (down 34 per cent to 163,000 in the year to June 2012). Although this still leaves the Government some way off their target of reducing net migration to less than 100,000 by 2015, ministers will be pleased to be able to say that things are, in their terms, moving in the right direction.

But there is a catch, and the simple maths of net migration mean that the current Government may be, wittingly or unwittingly, laying a trap for themselves, or for a future one.

Net migration is the difference between immigration and emigration.  So net migration rises if immigration goes up, or if emigration goes down; and falls if immigration goes down, or if emigration goes up.

The current falls in net migration are largely being driven by falling immigration, rather than rising emigration.  That falling immigration is, in turn, being driven in large part by a decline in student immigration (which accounted for more than half of the reduction shown in today’s statistics). More up-to-date Home Office figures show a decline in the number of student visas issued in 2012 of more than 20 per cent, which suggests that this trend will continue.

But most international students stay in the UK only for a short time, so they play an important role in driving emigration rates too. Reduced student immigration now will mean reduced student emigration in the future. This means that, although the short term impacts on net migration numbers are significant (because immigration falls before emigration), they are unlikely to be sustained. By 2015, this could halt, and even partially reverse, the falls we are seeing today.

This also means that even more drastic cuts to student numbers would be needed to make any further progress towards the Government’s target.  The Home Office’s own research suggests that only 18 per cent of student migrants are still in the UK after 5 years. That means that the 52,000 fall in student visas that we saw last year will only reduce net migration by a little over 9000 in the medium term. Given that the Government still need to reduce net migration by more than 60,000 in order to meet their target, it is clear that this cannot be achieved in the medium term without radical changes that go far beyond the student visa regime.

As a footnote, statistics released today by the Home Office suggest that international student numbers may not actually be falling as fast as the headline figures suggest. The number of student visitor visas issued rose by 11 per cent in 2012.  The Government has made more students eligible for these visas by allowing those coming to the UK to learn English to stay for up to 11 months as student visitors.  Although these short-term students don’t count as migrants in official definitions (and are thus, conveniently, excluded from the net migration target), they presumably have many of the same impacts (both positive and negative) as other international students. It is also noteworthy that the student visitor visa has less rigorous checks than the regular student visa route – for a government apparently so focused on reducing abuse of the student visa system, this might be expected to be a concern.

Sarah Mulley is Associate Director at IPPR.

Tags: Immigration, net migration, UK politics