My wife easily does 80% or more of the housework. She makes less than half what I do. The thing is, she only works 40 hours or so a week compared to my 60 or so. I'm not glorifying my overwork, I hate that I work so much. I'm also out of town during the week days more than half the time.
I would be thrilled if she made more than me. We could hire a cleaning service and we would be so happy. This shit is insane and probably bad science.