More than 1.44 million graduates have left the UK to look for more highly paid jobs in countries such as the United States, Canada and Australia. That far outweighs 1.26 million immigrant graduates in the UK, leaving a net "brain loss" of some 200,000 people.
The findings will fuel concerns that Britain's failure to defend its manufacturing, science and university base is pushing highly skilled workers overseas and risks damaging long-term productivity.
The scale of the emigration as a share of the total skilled workforce is also high. At 16.7 per cent - or one in six graduates - it is much higher than any other major industrialised country. In contrast, France has lost just 3.4 per cent of its graduates, the lowest level of any large country.
Frederic Docquier, one of the report's authors, said: "It does show an economic problem for developed countries. For countries such as the UK, a brain drain is clearly a loss. It may impact the rate of growth and the number of innovations that create growth in the long-run," he told The Independent.
He said the problem was exacerbated by the relatively low level of university education in the UK, which means the exodus of professionals is more keenly felt. Fewer than 20 per cent of Britons are educated to degree level and the figures are higher on the Continent - 27 per cent in Belgium, 25 per cent in Germany and 22 in France - and way below levels in the US.
His research suggested that British graduates were mainly moving to the US, Canada and Australia. "That is not surprising given the common language," he said.
But he said the sheer scale of emigration was much higher than rivals such as Germany. "Many Germans go to the US but the British are everywhere," he said. "You can go to any country and you will find a British graduate - that's why the figures are so high."
The most attractive destination is the US, which has 400,000 Britons followed by Canada and Australia with 365,000 each, and 200,000 in the rest of the EU. Some 120,000 go to other member countries of the Organisation of Economic Co-operation and Development which includes states such as Saudi Arabia and South Korea.
Graduates are even going to India to work in call centres. Last week, a survey found that UK graduates were prepared to fill an expected 16,000 Indian call-centre vacancies by 2009. A report earlier this year said a Scottish history graduate quit his £21,000 a year job for Sky Television to work in an Indian call centre.
Such clear evidence of the scale of the brain drain will worry employers such as engineering and pharmaceutical companies who need qualified graduates.
In August, a report for the Department for Education and Skills found that low pay, increased administrative duties and fixed-term contracts were causing leading academics to pursue their careers overseas.
So far even the World Bank's study is unable to show how many graduates various professions have lost. "This information is well-known to be hard to establish," Mr Docquier said. He said there was an urgent need for more research in the UK to find out if the exodus was more prevalent in "growth" sectors such as engineering, IT, medicine and academia compared with graduates generally.
He said there were signs of improvement. The emigration rate has fallen from above 20 per cent in the 1970s to 18 per cent in 1990 to 16.7 per cent now due to policies boosting education.
The report comes a week after official UK figures showed that the number of British citizens leaving the UK had hit a record of 208,000. The Confederation of British Industry highlighted the phenomenon of globalisation as enabling all businesses to look overseas for recruitment.
Jamie Anderson, 27: 'It's easier to be creative now'
By Arifa Akbar
Jamie Anderson moved to Greece two years ago after graduating in architecture from Heriot Watt University, Edinburgh.
In Athens, he found there were far greater opportunities and more creative projects.
"Architects go through a very long training process and I assumed I would be working by the end of the line. I spoke to some people in Britain and I was warned off it. They said you work long hours and do not reap the benefits of doing what you want to do.
"I remember sending out 50 letters in the UK and not receiving any job offers and only a couple of replies," he said.
He left Britain at the age of 25 in 2003, and found it easy to find work in Athens, which was preparing to stage the 2004 Olympics at the time.
"I joined a language class and it was through a friend of a friend there that I got my job in Greece. In the UK, it's extremely difficult to find a job, especially if have no experience. When I came to Greece, there were more opportunities," he said.
Having worked for several companies in Edinburgh over two years before moving to Greece, Mr Anderson was frustrated by the amount of paperwork and red tape that he encountered, compared to his work in Greece.
He works at Aiolou Architects, designing homes for foreign clients, and said that the work is far more creative than it would be in Britain.
"Whenever I was involved in designing anything in Britain, I reached this stumbling block of regulation, which often inhibited the designing and which wasn't very gratifying. In Greece, it is easier to be creative. I am able to do bigger projects and have more responsibility," he said.