A recent study by Maxim Pinkovskiy of M.I.T. and Xavier Sala-i-Martin of Columbia:

Our results show that the conventional wisdom that Africa is not reducing poverty is wrong. In fact, since 1995, African poverty has been falling steadily. Moreover, contrary to the commonly held idea that African growth is largely based on natural resources and helps only the rich and well‐connected, we show that Africa’s income distribution has become less rather than more unequal than it was in 1995, and therefore, that a great deal of this growth has accrued to the poor.
. . . .
Not only has poverty fallen in Africa as a whole, but this decline has been remarkably general across types of countries that the literature suggests should have different growth
performances. In particular, poverty fell for both landlocked as well as coastal countries; for mineral‐rich as well as mineral‐poor countries; for countries with favorable or with unfavorable agriculture; for countries regardless of colonial origin; and for countries with below‐ or above median slave exports per capita during the African slave trade.3 Hence, the substantial decline in poverty is not driven by any particular country or set of countries.