Plenty of studies have documented the brain drain: Highly educated workers migrate to richer countries, thus reducing the domestic return of education in poor countries. This phenomenon applies to all levels, within developing economies, from developing to developed economies and within developed economies. But it turns out some are actually subsidizing the brain drain.
Indeed, many countries would provide grants to their best students to study in the best universities, knowing full well that many of them will not return. The hope is that at least some will return, and this is worthwhile enough. The same applies to the high tech sector. For example, Finland encourages through FinNode young Finnish entrepreneurs to set up shop in the Bay Area and find collaborations there. The hope again is that some will return to Finland, knowing full well that some will stay in the United States and would not have tried without this help.
Of course, the United States is a net beneficiary in this, as it get free human capital. But the moral here is that subsidizing the brain drain can be a win-win sutuation.