In fact, it probably does more harm than good. The principal loss from prolonged work abroad is the fact that the professional is not contributing to the development of his own country. Instead, he is helping the rich get richer, thereby accentuating inequality among societies. The home country loses its investment in his upbringing and education before he left. Not only are the developing countries losing some of their most talented citizens, they are also losing the scarce capital that has gone into their rearing and training.
Education is, after all, an investment in the future.
In the case of brain drain from the developing countries, not only does the investment pay no dividends, but the very capital disappears. Moreover, the exodus of highly skilled professionals deprives the sending countries of the services of the persons on whom campaigns of economic and social development must be based. John Tanton, The Brain Drain and Countries of Emigration , 1979. In any society, change begins with people who are unhappy with the way things are. The democratization of the Soviet Union was brought about by those who were dissatisfied with its regime.