Equal Pay for Equal Work?

So I have a little problem with the educational system. And it goes like this. Females are more often given the job of teaching at a non-college level, whereas males are more often given jobs as professors at colleges. As if this isn’t bad enough, women are still getting paid less than men for teaching at every level, from elementary school to college. Why is this still happening? In my opinion, women and men should be getting equal pay for equal work.

Question: Why do you think women are still getting paid less than men? Do you support this? Why or why not?