Reforming migration policy will benefit Europe after the recession and address problems posed by ageing populations, according to a new UN report.
The 2009 Human Development Report says migration can benefit all concerned - those who move, those in destination countries and those who stay at home.
It says there is little connection between migrants and unemployment or wage decreases in local populations.
The report was commissioned by the UN Development Programme.
"Migration remains a contentious policy issue in need of reform and reconsideration across the European Union," said Jeni Klugman, lead author of the report entitled Overcoming Barriers: Human mobility and development.
She said she hoped the report would "help influence the debate and show the overall positive benefits of migration".
The report says the global recession should be seen as an opportunity for migration reform, especially for low-skilled workers.
It calls on countries receiving immigrants to tackle discrimination against them but also to address the concerns of local residents.
It proposes a package of reforms - such as reducing red tape and lowering passport costs - that would open up channels for migrants and safeguard their rights.
It points out that although the global population is expected to grow by a third over the next 40 years, nearly all this growth will be in developing countries while Europe's population will shrink and age.
The report says migration is one option for Europe's continued economic success.
Ms Klugman said the report contributed evidence and data to a debate that was "often driven by emotions and accusations".
Nearly one billion - or one in every seven - of the world's population are migrants, according to UN figures.