The truth behind UK migration figures

Heathrow border control

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Ever wondered how many people are moving to, and leaving, the UK? If so, you're not the only one - the official figures are said by some experts to be based on not much more than guesswork.

Yes, despite few issues mattering more to politicians and the public than migration, the UK still does not have an accurate system for counting people in and out.

The e-borders scheme - which was meant to do this job - is still a work in progress, and despite government assurances to the contrary, there are some who fear it might stay that way.

Instead the government relies on the answers given by a sample of travellers who agree to be stopped and questioned by a team of social survey interviewers at Heathrow and other main air, sea and rail points of entry to the UK.

And despite the increasingly high hurdles to jump through to get a visa to come to the UK, it seems there is no way of knowing if someone is still in the country when it expires.

UK population

Crowd of shoppers
  • According to the 2011 census there are 53 million people in England; 3.1 million in Wales; and 1.8 million in Northern Ireland
  • The figure for Scotland - and the whole of the UK - will be announced in December
  • The population of England and Wales has risen by 3.7 million in a decade - the largest increase since records began
  • The growth was fuelled by increased life expectancy, a rise in fertility rates and immigration
  • The 2011 census could be the last - the government is looking into cheaper and more responsive alternatives

Keith Vaz, chairman of the influential home affairs committee says he finds it incredible that a supermarket loyalty scheme can collect and store details on the shopping habits of millions of people, yet a similar database can not be set up to record arrivals and departures.

Particularly when the coalition government sets such store by reducing "net migration" - the difference between the number of people entering and leaving the country.

So if Britain does not count everybody in as they arrive, and count them out again as they depart, where exactly do the net migration figures announced each quarter by the government come from?

The main source is the International Passenger Survey (IPS), which was designed in the early 1960s to find out how much foreign tourists were spending in the UK - something it is still used for today.

It works something like this: There are about 240 IPS officials stationed at major airports and ports around the country.

They pick out every 10th, 20th or 30th passenger streaming through arrivals or departures, depending on how busy they are that day, and ask if they wouldn't mind taking part in a short survey.

"There may be times when, owing to a particular flood of passengers, you just cannot keep an accurate count. Do not panic if this happens but keep counting as best you can," advises the Office for National Statistics training manual.

'Hopelessly inadequate'

The ONS takes the raw IPS data and adds information about asylum seekers and migration statistics from Northern Ireland, as well as figures for people who have entered the country on short-term visas and decided to ask to extend their stay, before arriving at a final immigration figure.

About 300,000 people are interviewed each year by IPS officials - about 0.2% of the 200 million who enter and leave the UK over the same period.

The IPS has been considerably beefed up in the past three years, after it came in for stinging criticism from senior figures, including Bank of England governor Mervyn King, who branded it "hopelessly inadequate".

The ONS admits the survey is still not perfect but points out that 800,000 people are sampled to find the 300,000 interviewees and it has cast its net wider than Heathrow, where most interviewers were based, to other airports around the country and ferry terminals at Dover and Portsmouth it says 95% of travellers now "have a chance" of being interviewed.

It also has the virtue of being long established and relatively cheap.

But it is entirely voluntary and despite the training manual's advice to interviewers to be cheerful at all times - "no one wants to be interviewed by an unsmiling person with a dreary monotonous voice". Although the response rate is 78%, the ONS says that only 2% of people approached refuse to take part in it.

Passengers travelling at night, when interviews are suspended, or on smaller, low volume routes also slip through the net.

The one thing the IPS has over other sources of data on immigration - such as the number of non-EU passengers passing through border control, new NHS registrations or new National Insurance numbers - is that it records how long migrants say they intend to stay in the country.

Graph How accurate are the official net migration figures?

But its major flaw, according to experts, is when it comes to measuring how many people are leaving the country.

IPS emigration estimates are based on interviews with just 2,000 people (who, the ONS point out, are found from interviews with about 400,000 interviews) - and there is currently no alternative source of data to measure them against.

This matters because the coalition government has promised to reduce net migration - the difference between those entering and leaving the country - to "tens of thousands" by 2015.


Home Secretary Theresa May hailed "the first significant falls in net migration since the 1990s" in her keynote speech to the Conservative Party conference.

What she failed to mention was that when that "significant fall", from 252,000 to 216,000, was announced, the margin of error was also revealed for the first time.

What happened to e-borders?

Tony Blair
  • Tony Blair launched the £1.2bn e-borders programme in 2003
  • It was meant to collect details from passenger lists of all people entering and leaving the UK so that they can be checked against security watch lists
  • All flights from outside the EU are now part of e-borders
  • Ports and railway stations are due to follow by 2014
  • EU flights are meant to be covered by 2015
  • But that will depend on reaching voluntary agreements with other nations - and solving commercial problems
  • The US firm handed a £750m contract by Labour to deliver e-borders, Raytheon, was fired by the coalition in 2010 for "extremely disappointing" performance
  • The company is seeking £500m in damages from the government
  • The e-borders contract was split in two with IBM and Serco given the job of getting a system in place at nine airports before the Olympics
  • The contract for the post-Olympics element of the programme - the biggest part of it - has yet to be awarded

This showed that the main source of these figures was only accurate to within plus or minus 35,000 people.

In other words, according to the ONS, the fall was not yet statistically significant.

This does not mean, of course, that net migration has not fallen, just that, according to some experts, the government's main method of measuring its progress is little better than a rough guess.

"It is very difficult to assess how well the government is progressing toward its target of reducing net-migration to the 'tens of thousands', or to evaluate the effects of specific policy changes," says Dr Martin Ruhs, Director of the Migration Observatory at the University of Oxford.

"In simple terms the government could miss the 'tens of thousands' target by many tens of thousands and still appear to have hit it - conversely the government could hit, or even exceed its target and still appear to have missed it."

The government denies that the IPS is a faulty instrument for measuring its progress on migration.

In a statement to the BBC, Immigration Minister Mark Harper said: "The International Passenger Survey already provides the ONS with a reliable method of measuring net migration.

"By 2015, we aim to reintroduce exit checks using the e-borders system, which will allow us to build an even more accurate picture of the number of people entering and leaving the country."

A brainchild of the Tony Blair era, when it seemed as if there was no problem that could not be solved by a multi-billion pound IT project, e-borders was meant to replace the old paper-based embarkation system, which was scrapped in the 1990s.

Since then departures from the UK have not been officially recorded.

So it is possible for migrants to enter on short-term visas and - unless they notify the authorities of their intention to stay longer or are really, really unlucky and are picked up in a Border Force raid - stay in the UK or leave the country years later without showing up in the official records.

It was one of the justifications Mr Blair made - and is still making - for the introduction of an identity card system.

E-borders which was primarily meant to improve security, when combined with a biometric identity card scheme, began collecting details of passenger and crews for inbound flights from outside the EU at nine airports in March.

The plan now is to extend it to ports and railway stations by 2014 and to passengers from within the EU by 2015.

But that will depend on persuading all EU countries to share passenger and crew list information - quite a number of them regard this as illegal under European free movement laws.

High hopes

And there are some, such as Keith Vaz and Sir Andrew Green, of think tank Migration Watch, who fear the project, which was meant to be up and running in time for the Olympics, may have stalled altogether.

"The government will rightly be held to account if they fail to achieve a steady and substantial reduction in net migration, whatever the technical details," said Sir Andrew.

"But it is time we were told more about the purpose and progress of the e-borders programme."

The statisticians at the ONS still have high hopes that e-borders will one day be able to provide reliable migration statistics.

But they say it will be 2018 at the earliest before they can even start incorporating data from the programme into their estimates - and there are no plans to replace the IPS as the main source of migration data.

So until the Home Office can be persuaded to come up with a different method - the men and women of the IPS will continue to put on their best smiles and try not to panic as they scan the arrivals halls of Britain's ports and airports.

And net migration statistics should continue to be taken with a major dose of salt.

Graph showing increase in migration

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  • rate this

    Comment number 34.

    @24 Worried pensioner: spot on! And while we're talking about the need for a true picture let's identify the numbers of Brits who "emigrate" because they can't stand it here and then come back when conditions in their chosen promised land turn against them or they news NHS treatment. I have no time for those who abandon the UK while we all stay, and then expect to return to all the benefits.

  • rate this

    Comment number 33.

    What it demonstrates is that for all the governments’ talk of controlling the numbers it amounts to just a lot of wind aimed at those gullible enough to believe it and vote accordingly. In other words the Conservatives are no less guilty than Labour of burying their heads in the sand on this issue.

  • rate this

    Comment number 32.

    It is quite gratifying that we hear that government can't count peopel in and out of the country. There are lots of other things government can't count. This makes me more confident that command and control techniques put in place by Blair failed and as an individual I enjoy a certain freedom, against government design.

  • rate this

    Comment number 31.

    Poor book work and too few resources to track those in and those out. It's amazing how the Civil service failed to do what was required. Privatising parts of the immigration service has not encouraged a joined up approach and lack of fast profit means resources are further cut by these companies. Result no accurate figures.

  • rate this

    Comment number 30.

    We all have a passport with a unique number on them (and I assume so does every other country), so why not just take a record of that number when someone arrives, and delete it when they leave ? That way, you'd know how many people from outside the UK were in the country at any one time - and, indeed, who they were.

    Sounds very, very, very simple to me - so why is it so hard then ?

  • rate this

    Comment number 29.

    Years ago, a Home Office official was on R4 today extolling the virtues of unfettered immigarion. The reason we are so inept is that he Home Office want it that way, it fits their prejudices.
    The taxpayer of course picks up the bill. Affordable housing, anyone?

  • rate this

    Comment number 28.

    "Ever wondered how many people are moving to, and leaving, the UK? "

    Think of a number, double andthen add some noughts. That should do it.

  • rate this

    Comment number 27.

    Even if they can get all the controls to work its far too little far too late.
    10 years ago was when immediate action was required.
    During that period lots of eastern block immigration which was unchecked. Schools were swamped by big rises in numbers of children who couldn't speak English.
    These hordes were welcomed by Bliar and Brown for their votes.
    NuLiebour- never again.

  • rate this

    Comment number 26.

    What really does beggar belief is that we have no real idea who is coming in and out.

    I personally have no objection to anyone etering the country if they intend to work, integrate and contribute to society. We have more than enough natives who have no intention of working and contributing.

    What we do need to know is the numbers. Shouldn't be hard on an island... should it?

  • rate this

    Comment number 25.

    We champion freedom of speech around the world, and yet people are scared to speak out in the UK, what irony.

    2525 in 2012.

    Ain't gonna need to tell the truth, tell no lie, everything you think, do and say, is in the pill (or the media) you took today

    Not sure these numbers matter as much as increased welfare payments, and UK jobs going to non-uk citizens …. And we can count these.

  • rate this

    Comment number 24.

    Thank goodness for immigrants. Without them, who would look after us in our old age. Who would provide the working age population to support us financially. Immigrants are usually the brightest, best and most industrious from their country of origin. Yes, by all means control the rate of immigration, but do not throw out the baby with the bathwater.

  • rate this

    Comment number 23.

    this is strange as UK doesnt want to be part of Schengen where all the countries have exit checks but yet it is not there in the UK

  • rate this

    Comment number 22.

    Control over those who come here legally seems irratic enough but what about all the illegals?
    Do so few understand that we cannot stop immigration or properly control our borders all the while we are members of the EU.

  • rate this

    Comment number 21.

    The UKBA is massively underfunded, understaffed and morale is low amongst its employees. The angency is being privatised through the backdoor with businesses coming in, doing rubbish work and then leaving government employees to clear everything up. Then there's the fact that people will always be untraceable and disappear into their own communities working for the family business etc.

  • rate this

    Comment number 20.

    The Americans can fingerprint and check everyone and send people back on next plane why not us

  • rate this

    Comment number 19.

    no man is an island but he may be a penisula
    if stop tv and radio broadcating etal then nobody would come here and we can be cosy

  • rate this

    Comment number 18.

    Along with the state of the economy this is the hottest political issue IMHO and, when the time comes, the party with the most workable reduction policy will get my vote. We need an open and meaningful national debate about this without fear of the loony liberal left hurling accusations of racism and bigotry at all and sundry. Our Commonwealth cousins down under in Oz can teach us a thing or two!

  • rate this

    Comment number 17.

    Well I'll be flamed for this. I live in Tower [s]Hamlets, a failed 3rd world statelet in the East End. Population rise about 25% in the last few years in the most densely populated and deprived borough in the capital. Meanwhile the borough 'response' is whining about overcrowding and allow the more office building on the city fringes. Out of control doesn't even begin to cover it. Go figure!

  • rate this

    Comment number 16.

    "Hopelessly inadequate" all that needs to be said except there has been no will whatever from any governemnt to comit the resources needed to properly control our borders. The old "we need all these people" is valid only to exploit those who work cheap for private sector. The national cost to public resource NHS & Infrastructure is massive. What bit of the country is full dont they understand.

  • rate this

    Comment number 15.

    I thought this lot in government promised that they'd start counting in and out. They must be too busy putting the brakes on economic grwoth.


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