The "brain drain" phenomenon has a long history. In 1963, the Royal Society defined "brain drain" the exodus of British scientists to USA, seriously jeopardizing the British economy, but this term eventually became of common use to describe the emigrations of scholars and professionals from the Third Word countries. Because of these migrations, the investments made by these countries on the formations of their nationals were used by the developed countries: the results was an unjust technological aid to the richer countries by the poorer ones. This concept of "reverse technological transfer" was developed by the United Nation Conference on Trades and Development on 1972. After the end of the Soviet Union and of the Warsaw Treaty in the last decade of the past century, an huge brain drain started from the Eastern European countries; at the same time, a serious risk of brain waste is present nowadays, since not all the migrants are able to find a job at the level of their skill. A number of scholars suggested that it is now more appropriate to define the high skilled migrations as "brain mobility" and not as "brain drain", since, to date, the Word economy is largely dominated the free circulation of capitals, merchandise and job. However, many others are still convinced that the concept of "brain drain" is still valid, mainly in case of migrations of highskilled workers from Third Word countries to the North.