Gender pay gaps across STEM fields of study / Tomasz Zając (University of Queensland), I. Magda (SGH Warsaw School of Economics, IBS Institute for Structural Research and IZA), M. Bożykowski (University of Warsaw and National Information Processing Institute), A. Chłoń-Domińczak (SGH Warsaw School of Economics), M. Jasiński (University of Warsaw and National Information Processing Institute) ; IZA Institute of Labor Economics