Returns to postgraduate education in Portugal : holding on to a higher ground? / André Almeida (CIPES), Hugo Figueiredo (CIPES, University of Aveiro and GOVCOPP), João Cerejeira (CIPES, NIPE and University of Minho), Miguel Portela (CIPES, NIPE, University of Minho, IZA and Banco de Portugal), Carla Sá (CIPES, NIPE and University of Minho), Pedro Teixeira (CIPES, IZA and University of Porto) ; IZA, Institute of Labor Economics. Bonn, Germany : IZA Institute of Labor Economics, March 2017