High levels of migration might not always be good for community relations if large numbers of new arrivals descend on one neighbourhood, but at least it helps boost GDP by providing Britain with a source of eager workers whom employers struggle to find in Britain. That sums up the view of some economists, but it has just been thoroughly rejected by one important voice. David Miles, who sits on the committee of the Office for Budgetary Responsibility (OBR), has written today that it is wrongheaded to think that Britain can solve its economic problems by opening its doors to overseas workers.
One of the arguments frequently made in favour of open-door migration is that it helps tackle the problem of an ageing population - because migrant workers tend to be youthful. Yet, according to Miles' calculations, even if every single migrant arriving in Britain were aged 24, Britain would have to accept 20 million of them over the next 40 years in order to preserve the population balance as it currently is. And of course, as he says, 'today's young people are tomorrow's old people'. By the end of those 40 years, migrants who arrive today aged 24 will be close to retirement age. They will be on the point of claiming pensions themselves. All you would have achieved by opening the doors to them is to create another population bulge like that of the baby boomers who are currently retiring and thus helping to swell Britain's non-working age population.
Moreover, not all migrant arrivals are, of course, aged 24. Those who come to work in Britain often bring non-working dependents. Even those who are working consume public services, helping to put further pressure on overstretched schools, hospitals and housing. What would be far more fiscally beneficial, says Miles, would be investing in getting far more of Britain's working-age population back into work. Repeating a point made by many others, it is counter-productive to sign off 'on the sick' the growing numbers of people who claim to be too mentally unwell to be expected to work for a living. 'There is a great deal of evidence that mental health in particular is typically improved by being in work,' he writes.
Accepting a migrant into the country may help provide the economy with an extra worker, but getting someone who is out of work back into work is doubly advantageous from the fiscal point of view: not only does it provide an extra worker to boost output, it also reduces spending on benefits.
Those who still argue that migration boosts the economy must answer an awkward question: why, if that is the case, is the UK economy bouncing along the bottom in spite of net migration of 700,000 a year? If migration were an important factor in economic growth it would surely be boom time. What we won't know - but could be crucial - is the relationship between high rates of migration and rising numbers of people on out-of-work benefits. Does the former cause the latter by making it harder for UK citizens to find gainful employment and encouraging them to apply for welfare instead?
The debate regarding migration is beginning to change. Until recently, the anti-migration lobby was accused by some of being economically illiterate. Yet the OBR now calculates that a low-wage migrant - assuming they stay in Britain - will eventually cost the UK taxpayer £1.55 million, as the pensions and benefits that are paid to them will outweigh the taxes they pay during their lifetime.
Even a migrant on the average UK wage will end up costing a net £405,000. As we saw in last autumn's Budget and in the spending review in March, the OBR's forecasts are crucial to the Chancellor's thinking - Rachel Reeves tailors her tax and spend policies to forecasts of fiscal headroom and fiscal black holes. Now that the OBR seems to be leaning away from viewing mass migration as a means of boosting the economy, it will presumably have a sharp effect on government migration policy.