The British government's attitude towards immigrants, especially those with badly needed skills, has undergone major changes in recent years, according to a report, International Mobility of the Highly Skilled , published by the Organisation for Economic Cooperation and Development.
"Managing migration to the United Kingdom's benefit is now the driving force. The official debate has started," writes Nicholas Rollason of law firm Kingsley Napley.
In the face of acute skills shortages, particularly in information technology, changes to work permit and immigration arrangements have been introduced and skills criteria reviewed. Efforts have been made to attract entrepreneurs and the highly talented.
The report quotes a government minister as acknowledging that Britain competes with other countries for the brightest and best - those "who make the whole economy tick".
The minister says: "In order to seize the opportunities of the knowledge economyI we need to explore carefully their implications for immigration policy."
The study reports that there was a big increase in the international mobility of the highly skilled in the 1990s. It suggests that this had a big impact on the performances of countries in the science and technology field and therefore on growth.
"However, these effects remain unequally distributed, especially between sending countries (mostly developing countries) and receiving countries," says a foreword to the study.
"As a result, policies aimed at facilitating the recruitment and mobility of highly skilled workers, in particular migration policies, must endeavour to ensure a fairer distribution of benefits."
Countries receiving these workers benefit from the stimulation of innovation capacity, an increase in the stock of available human capital and the international dissemination, the report suggests.
The loss of human capital by countries is offset by the eventual return home of migrants, the development of networks helping the circulation of skilled workers between host countries and their country of origin, and money from remittances.
But the brain drain in developed countries may be exaggerated because many emigrants eventually return. Temporary labour migration is becoming increasingly frequent, especially in Australia and the United States.
International Mobility of the Highly Skilled, OECD, €60 (£37) www.oecd.org