The brain-drained countries

Immigration has become a buzzword in the recent weeks. No one, however, is talking about the inverse – emigration, more specifically, the brain-drain. Africa, amongst other developing nations, is losing its doctors, engineers, professors and other skilled professionals to its detriment. The reasons for this drain is literally a no brainer.  Political instability is one factor but then there is the attraction of higher pay and better opportunities in the West.  1 in 9 Africans with a tertiary education are living in Europe, North America and elsewhere. 
The global local village we live in today requires us to look at immigration from both perspectives – emigration and immigration. At best there should be a mutually beneficial ‘exchange’. One side of the world shouldn’t suffer whilst the other thrives.
Mocca Mums, what could be done to retain talent or regain it after a period of time away?