The concept of “brain drain” is in its origins a nationalistic concept, by which is meant a concept that visualizes economic and cultural welfare in terms of the welfare of the residents of a national state or region, viewed as a totality, and excludes from consideration both the welfare of people born in that region who choose to leave it, and the welfare of the outside world in general. Moreover, though the available statistics are far from adequate on this point, there is generally assumed to be a net flow of trained professional people from the former colonial territories to the ex-imperial European nations, and from Europe and elsewhere to North America and particularly the United States. The concept thus lends itself easily to the expression of anti-colonial sentiments on the one hand, and anti-American sentiments on the other. The expression of such sentiments can be dignified by the presentation of brain drain as a serious economic and cultural problem, by relying on nationalistic sentiments and assumptions and ignoring the principles of economics—especially the principle that in every transaction there is both a demand and a supply—or by elevating certain theoretical economic possibilities into presumed hard facts.