Because women are more likely to seek part time work than men they are more likely to fall into casual positions.
I have some moral issues with employers hiring women for fixed times positions as casuals rather than permanent part timers. I seems to result in neither party taking the position as seriously as it should.
I think that they are paid more as casual, I may be wrong on this point. this makes up for the annual leave entitlements etc.
means they can go on holidays when it suits them also be able to be at home in school holiday time