I know for a fact that men are paid more because I found out what a co-worker made when we were both doing the same job, for roughly the same amount of time ( I was there longer) and with the same educational background.  Perhaps in strictly structured union industries what you are saying is true, but so many jobs are not structured this way. When I brought up the discrepancy with my boss in my review, his concern was how I knew what my coworker's salary was. I was a good worker and at the risk of sounding self absorbed, a better worker than this guy-yet they paid him more.