In our Social Structure class we are considering Barbara Reskin's "Labor Markets as Queues" and Warren Farrell's Why Men Earn More.
Reskin notes that an occupation draws more women when it is "deskilled." This also leads to pay going down. She treats this as evidence of discrimination against women.
Farrell notes that an occupation draws more women when the task is made easier and working conditions get better. This also leads to pay going down. He treats this as evidence of what happens when the supply exceeds the demand for a job.
In general, Reskin treats lower women's wages as discrimination against women, even though it costs employers more to hire men at higher wages.
Farrell points out that if employers could really get the same work from women, or any kind of workers, for lower wages, the employers would hire them. If it is not illegal to hire from the less-likely group, then some employers will break ranks with custom to save money and reap a competitive advantage.