R. J. Rummel at Democratic Peace has an interesting post discussing the failure of Africa. He (or rather, a commenter) suggests taking a look at tribal culture.
Those of us from more individualistic backgrounds assume that our accomplishments, our savings, our capital accumulations and our property are our own--to keep and use as we see fit. But the tribal staff members were powerless to resist the demands of their families, and other members of their tribes, who immediately made claim to what they perceived as the accumulated wealth of their compatriots.
What good will starting a successful business do if tribal culture demands this wealth be shared among tribesmen? Compare to America, where a new and successful business will likely benefit the "tribe" (community), but in a distinctly different way. The business becomes so big that help is required, so someone from the community offers to help the business, in exchange for a fair wage.
Of course, I was all over this topic, as you can see in my advice to Axis of Evil Overlords:
4. Before I appoint my son, brother-in-law, or other member of my tribe to a position of power, I will first check to see if someone better qualified is available.