Is that the case? Or is it that men leave a field when the pay begins to drop? Distinguishing between cause and effect is very important in these matters. I don't see anything here to suggest the authors have established the cause and effect relationship.
Exactly what I came here to say. Ramp up STEM grads? Pay drops. Ramp up attorney grads? Pay drops. Ramp up workforce in a sector? Pay drops. Adding women to the marketplace for a particular job significantly increases competition for employment. As an example, if a bunch of pro-male motivational speakers went out and encouraged men who currently have very dangerous jobs to move into nursing en mass, and the spots in nursing schools weren't artificially limited (they are, in reality), the pay would drop.
