Not really, but Wal-Mart should consider it.
In the current class-action lawsuit against Wal-Mart that has just been certified by a federal appeals court: “The plaintiffs allege that women were paid less than, and were given fewer opportunities for promotion than, their male counterparts.”
If women are willing to work for less than men, then clearly Wal-Mart should hire only women to reduce labor costs. For more on the “pay gap,” see Walter Block.