[Thorrez]

>It doesn't suffice to explain how a sex pay gap could emerge. If hiring men were more expensive (because they have greater opportunity costs), then just don't hire them--hire the women, or whomever is willing to accept the wage you're willing pay for the particular labor services desired.

Yes exactly. It would only explain a pay gap at the low end of the pay scale. It wouldn't explain it in the middle or high end.