Bluematter.

Burning our money, in a venomous post with a number of ridiculous assertions, asks whether immigrants have made 'us' (indigenous Britons) richer:

Has it (immigration) made us richer?

* No: overall GDP per head has been little changed by immigration

The most widely quoted study is still the one published by the highly respected National Institute for Economic and Social Research (NIESR) last year (and see their Lords submssion here). They reckoned that immigration between 1997 and 2005 had raised GDP by 3.1%. But since it had increased the population by 3.8%, GDP per head had actually fallen.

Why might that be?

First, because many of these new immigrants take low-skilled jobs which produce less than the average UK worker. High productivity investment banking immigrants are very much the exception.

Second, they displace indigenous workers who join the dole queue (eg see this blog on the problems in Slough where hungry incomers from Eastern Europe consigned existing Pakistani immigrants to an 18% fall in their employment rate in three years).

I won't question the facts he quotes or address the morality of the issue (as an immigrant, I suffer from many defects including attention deficit disorder). But this guy can't even get his algebra right.

He presents the fall in GDP per capita that is attributable to immigration as proof that immigration does not make us richer. But, of course, it is perfectly conveivable for immigration to be making EVERYONE better off (both the indigenous population and the immigrants) while leading to a lower GDP per capita. How?

Let's say what's his name is the sole inhabitant of Britain and he earns (produces) £100 a year. GDP per capita in Britain in this scenario is £100 pounds.

Now let's say I come to live in Britain, from a country where I was earning £20 a year, and I now earn (produce) £30 a year. Let's also say that, because of immigration, what's his name now earns £150. GDP per capita in Britain is now down to £90 from £100, yet we are all much, much better off.

Ah, the wonderful things you learn in primary school when you are not busy harassing little Johnny immigrant...