Companies don't think that women are cheaper. They might pay them a bit less on average, but they see them as potential liabilities because they might get pregnant or leave or reduce hours to have a family.
This brings up my favorite Pregnancy leave story. We are required to allow a woman to take leave after having a child, and some take extended leave, something like a year. I really have no issue with this, seems like a good idea.
We had a staff assist who over a several year period, had three children, and took the max leave. SO out of six plus years, she was there around half of the time.
Well, there was a real need for someone when she was away form work, so they hired a temporary replacement. three of them.
Guess who lost their job every time this woman came back to work? Three women lost their jobs because of her legitimate and legal extended maternity leave. I guess that is the law of unintended consequences.
No particular political import, just something the thread reminded me of.