Magnum

ITALIANS blame gypsies from Romania for a spate of crime. British politicians of all stripes promise to curb the rapid immigration of recent years. Voters in France, Switzerland and Denmark last year rewarded politicians who promised to keep out strangers. In America, too, huddled masses are less welcome as many presidential candidates promise to fence off Mexico. And around the rich world, immigration has been rising to the top of voters' lists of concerns—which, for those who believe that migration greatly benefits both recipient and donor countries, is a worry in itself.

As our special report this week argues, immigration takes many forms. The influx of Poles to Britain, of Mexicans to America, of Zimbabweans to South Africa and of Bangladeshis to the Persian Gulf has different causes and consequences in each case. But most often migration is about young, motivated, dynamic people seeking to better themselves by hard work.

History has shown that immigration encourages prosperity. Tens of millions of Europeans who made it to the New World in the 19th and 20th centuries improved their lot, just as the near 40m foreign-born are doing in America today. Many migrants return home with new skills, savings, technology and bright ideas. Remittances to poor countries in 2006 were worth at least $260 billion—more, in many countries, than aid and foreign investment combined. Letting in migrants does vastly more good for the world's poor than stuffing any number of notes into Oxfam tins.

The movement of people also helps the rich world. Prosperous countries with greying workforces rely ever more on young foreigners. Indeed, advanced economies compete vigorously for outsiders' skills. Around a third of the Americans who won Nobel prizes in physics in the past seven years were born abroad. About 40% of science and engineering PhDs working in America are immigrants. Around a third of Silicon Valley companies were started by Indians and Chinese. The low-skilled are needed too, especially in farming, services and care for children and the elderly. It is no coincidence that countries that welcome immigrants—such as Sweden, Ireland, America and Britain—have better economic records than those that shun them.

Face the fears

Given all these gains, why the backlash? Partly because politicians prefer to pander to xenophobic fears than to explain immigration's benefits. But not all fear of foreigners is irrational. Voters have genuine concerns. Large numbers of incomers may be unsettling; economic gloom makes natives fear for their jobs; sharp disparities of income across borders threaten rich countries with floods of foreigners; outsiders who look and sound notably different from their hosts may find it hard to integrate. To keep borders open, such fears have to be acknowledged and dealt with, not swept under the carpet.

Immigration can, for instance, hurt the least skilled by depressing their wages. But these workers are at greater risk from new technology and foreign goods. The answer is not to impoverish the whole economy by keeping out immigrants but to equip this group with the skills it anyway needs.

Americans object to the presence of around 12m illegal migrant workers in a country with high rates of legal migration. But given the American economy's reliance on them, it is not just futile but also foolish to build taller fences to keep them out. Better for Congress to resume its efforts to bring such workers out of the shadows, by opening more routes for legal, perhaps temporary, migration, and an amnesty for long-standing, law-abiding workers already in the country. Politicians in rich countries should also be honest about, and quicker to raise spending to deal with, the strains that immigrants place on public services.

It is not all about money, however. As the London Tube bombers and Paris's burning banlieues have shown, the social integration of new arrivals is also crucial. The advent of Islamist terrorism has sharpened old fears that incoming foreigners may fail to adopt the basic values of the host country. Tackling this threat will never be simple. But nor would blocking migration do much to stop the dedicated terrorist. Better to seek ways to isolate the extremist fringe, by making a greater effort to inculcate common values of citizenship where these are lacking, and through a flexible labour market to provide the disaffected with rewarding jobs.

Above all, perspective is needed. The vast population movements of the past four decades have not brought the social strife the scaremongers predicted. On the contrary, they have offered a better life for millions of migrants and enriched the receiving countries both culturally and materially. But to preserve these great benefits in the future, politicians need the courage not only to speak up against the populist tide in favour of the gains immigration can bring, but also to deal honestly with the problems it can sometimes cause.