I don't usually refer to brain drain in my understanding of things. If this is true, I should. But why expect differential brain drain between Africa and Asia, which is what is necessary to explain this.
I endorse Lumifer's reason. Other reasons would include less patriotism (as I understand, loyalties in much of Africa are to tribes/clans/families rather than a nationstate, religion, or ideology, so bringing your family abroad of going abroad to look for money would be less of a shift) and less perceived safety (e.g. apparently 75% of Ethiopia's skilled laborers moved abroad during its famines).
People want to tell everything instead of telling the best 15 words. They want to learn everything instead of the best 15 words. In this thread, instead post the best 15-words from a book you've read recently (or anything else). It has to stand on its own. It's not a summary, the whole value needs to be contained in those words.
I'll start in the comments below.
(Voted by the Schelling study group as the best exercise of the meeting.)