By Mark Wallace
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Early in June, I wrote a reply to a Peter Kellner article in which he lamented that the public are illogical and don't trust official statistics. "Don't pity the rational politician – applaud the sceptical electorate. They are often absolutely right" was my conclusion, given years of misleading data – particularly on immigration.
Today, a new report from the Public Administration Select Committee reveals that the statistics those claims are based on are little better than a guesstimate. Rarely have I been more frustrated to be proved correct.
The Government's pledge to reduce net migration is a key plank of the next election campaign – CCHQ regularly issues infographics and updates reminding everyone that the Coalition's record starkly contrasts with Labour's incompetence in border control. If real doubt can be cast on those claims then it would be politically disastrous.
Given the queues at airports and the grumpy insistence of the border officers on scanning everyone's passport, we tend to imagine that the number of people coming into the country is at least counted. Apparently, it isn't – rather, the official statistics are based on a survey of people arriving in the UK.
The sample size means that only around 5,000 migrants are surveyed each year. As the committee chairman, Bernard Jenkin, rightly points out, they might not have much incentive to tell the truth when asked about their intentions when quizzed by officials.
Such surveys fail to even properly record legitimate migration, still less illegal immigration. An implicit message from the Home Office's "Go Home" vans is that there are so many illegal immigrants in the UK that the Government believes a van driven down any given high street will pass several of them as it does so.
Philippa Roe, the leader of Westminster City Council, says that Disneyland keeps better track of its visitors – it is hard to argue with her claim, which shows the seriousness of the issue.
It may be that the Home Office is right to claim that the Government's border and immigration reforms are working (at least in reducing migration from outside the EU – it is all too rarely mentioned that we still have no control of our borders as far as European migration is concerned).
The problem is that, as Paul Goodman reiterated yesterday, voters are already suspicious of claims about falling net migration – and this weak methodology will make it even harder to persuade them. If this problem isn't fixed, the electorate will be out to punish the Government for yet another failing on immigration – and UKIP will undoubtedly be hawking for their votes, today's headlines in hand.