... 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.
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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.
AAAARGH! 
