Why is it more expensive to send money to Africa?

Why is it more expensive to send money back home to Africa as remittances than anywhere else in the world? Community leaders in western Kenya say they have found a way they hope will reduce teen pregnancies - by giving school girls bicycles and we look into sex robots, apparently a phenomenon of the future, but do they have a place in Africa?

(Photo: Woman collecting money. Credit: Mohamed Abdiwahab/AFP/Getty Images)