I've seen this first hand. I was hired into my position straight out of grad school. I noticed one of my colleagues (a black woman) was in a position below mine that paid about $20k less even though she had all the same knowledge and skills that I had. She had a PhD and had done a post-doc while I never even finished my PhD. She's older, more experienced, and better educated, yet somehow not qualified for my position.

I asked my boss about this and he said it was because this was her first real job. When I reminded him that this was also my first real job he just said "that's different" without further explanation.