Remittances and the brain drain : evidence from microdata for sub-Saharan Africa / Julia Bredtmann (RWI, IZA and CReAM), Fernanda Martínez Flores (RWI and Ruhr University Bochum), Sebastian Otten (University College London, CReAM and RWI) ; IZA. Bonn : IZA, November 2016