Now in charge of a huge aid budget that rewards economic and political improvements in developing countries, Yohannes arrived in the US in 1970 and worked his way to the top of the banking profession.
As chief executive of the Millennium Challenge Corporation (MCC), he is a powerful voice for Africa in Washington DC.
By linking aid to good governance, the MCC rewards reforming governments on the continent and across the globe.
The corporation is now reflecting on how it got it wrong on Mali, as corruption and an ineffective state apparatus under President Amadou Toumani Touré contributed to the country's current political turmoil.
Our list of influential people in Africa will certainly be disagreed with. Why is this fantastic woman not included? How could this master-of-the-universe have been forgotten? This debate is certainly...