Policy drives evidence in modern political debate.  Nowhere is this more true than in discussion of the economics of immigration to Britain.

In 2007, the then Home Secretary lauded ‘the purity of the macroeconomic case for migration’ and the Immigration Minister claimed that ‘there are obviously enormous benefits of immigration’.  He even quantified the benefit at £6bn per year, (though this is hardly ‘enormous’ relative to GDP of £1.5 trillion). Official predictions grossly underestimated the numbers who would come when the border was opened to Poles in 2004

         By 2012, however, the Home Secretary was claiming that without immigration, house prices would be lower, wages higher, and that every 100 immigrants put 23 British workers out of a job. Official predictions appear to have grossly overestimated the numbers who would come in 2014 when the borders were opened to Bulgarians and Romanians.

What had changed between 2004 or 2007 and 2012 and 2014 was not that new facts about immigration had become available. Nor had new analysis led to a reversal of earlier conclusions.  What had changed was the complexion of the government, the identity of the Home Secretary, and the salience of immigration as a political issue.

The composition, mode of selection, and even the existence of the House of Lords are difficult to defend.  But its Economic Affairs Committee, which is willing to tread fearlessly in controversial areas, is a bright spot in our political darkness.  The Committee’s 2008 report on the economics of immigration provides a balanced and careful assessment.  Its conclusion is that at the aggregate level neither the net costs nor the net benefits of moderate levels of immigration are very large.  There are significant economic issues raised in the immigration debate, but they are of a much more granular kind.

        It is hard to imagine that even the most philistine and xenophobic drinking companion of Nigel Farage thinks Britain should have prevented the immigration of Ernest Rutherford from New Zealand, TS Eliot from the United States, or Ludwig Wittgenstein from Austria. Both Karl Marx and Friedrich von Hayek chose to write their principal works in Britain, recognising a freedom of thought that has contributed to both intellectual and commercial success.  Immigration has made London today the most cosmopolitan city in the world, possibly the most cosmopolitan city that has ever existed. 

      The economics and sociology of immigration are inextricable.  How else can you explain that in Britain more than 80% of people born in Eastern Europe, and less than 20% of women born in Bangladesh, are in employment? 

       Immigrants are, by virtue of the self selection that leads some to move countries while others stay at home, more than averagely enterprising:  the immigrant who takes our job is a more real threat than the immigrant who scrounges our benefits.  Perhaps the history of immigration helps explain why Americans are  even now more individualistic and more innovative than the populations of the  European societies which many of their ancestors left.  This process of selection explains the phenomenon of the economically successful immigrant minority:  the  Huguenots in Britain and the Netherlands, the Chinese in Malaysia, Jews in many countries, and the Indians who prospered in Africa and thrived when expelled to the UK. And the resentment felt among the indigenous majority.

The affirmation of group identity is a powerful human emotion, and one that is often useful, if perhaps less useful than it was on the savannahs.  Politicians, like gang bosses and football supporters, routinely attempt to establish or reinforce their leadership positions by inciting hostility to other groups.  This is an especially attractive strategy when the group feels under economic pressure.

The most powerful antidote to these movements is not sermons on the values of tolerance, or essays on multiculturalism.  It is friendship and above all love and marriage between individual members of potentially hostile groups.  Many religious, cultural and linguistic practices inhibit the formation of such relationships.  Often, that is why group leaders – segregationists, mad mullahs, or self-appointed representatives of minority communities, emphasise these mechanisms of separation. 

Romeo and Juliet might have bought Montagus and Capulets together through a happy marriage, but did bring them together through their tragedy:  and it is obvious which is the better route.  America is the most successful of immigrant societies because its immigrants aspired to be Americans:  and its greatest social problem stems from its attempt to deny that opportunity to one particular racial group.