tempsperdue, it applies to private sector employers with 10 or more employees, and has for 30 years.  [congratulations for finding this out during the comment-editing period ;-)  ]  Perhaps the fact that it has -  without big problems coming to your attention - might suggest that it's not causing the kind of problems you suggest.  It was needed because the people setting wages in the first place - employers - had historically undervalued women's work.  The unseen hand of supply and demand isn't quite so value-free as you seem to think.