“Do men conspire to keep the pay of the women at low levels? No evidence indicates that this has occurred. What about the theory that senior management purposely keeps men’s pay higher? There is little proof of this either, though several legal cases make this claim.

‘Alas, no one has those data, as companies tend to be very secretive about this,” says Arian Hegewisch, Study Director at IWPR. “The best information in theory might be sex discrimination law cases against specific companies, but even there, unless cases are litigated by the EEOC, typically wage and salary data are kept under wraps.'”