The UK is failing to retain “super-mobile” workers as immigrants move on because of the economic downturn, according to a report to be published today.

Super-mobiles are the brightest of the foreign workers who arrive in Britain and stay for less than four years, the study says. They move several times in their lifetimes to take advantage of globalisation. The study suggests that tax breaks be introduced to encourage talented workers to stay and that efforts be made to persuade Australians and New Zealanders who arrive in Britain as part of the “Big Overseas Experience” to remain permanently.

About half the six million immigrants who arrived here in the past 30 years have since left, according to the report by the Institute for Public Policy Research. Tim Finch, from the think-tank, said: “The migration debate is fixated with the idea that immigrants come to settle and not enough attention has been paid to the fact that more and more are spending only short periods in the UK.

“Migrants are coming to study and work for short periods and then moving on. As global competition for highly skilled migrants increases in future years, schemes to retain migrants may become as important as attracting them in the first place.”

Migration in which people remain for less than four years doubled between 1996 and 2007; most were students or from countries that joined the EU in 2004. Only a quarter of migrants who arrived in 1998 were still here in ten years later, the report says.

The report warns of increasing competition from other EU countries also keen to attract bright migrants. It recommends that schemes to help students find work be extended and that highly skilled migrants who are committed to remaining here be given extra points. It also suggests that it be made easier for skilled migrants to renew their visas or work permits and for their families to join them in the UK.