It seems that the most likely explanation for the pay gap is the gap in dedication and energy spent at work. Until recently, many studies had found a bias against hiring women women in education and tech. But once corrected for lifestyle/marital status (i.e. single men without children compared against single women without children, etc), we observe the opposite picture. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4418903/pdf/pna...