Sexual Discrimination at Smith College?

At Smith College, where I teach:

The average female professor makes $77,611, while
The average male professor makes $88,315.

Some feminists believe that if a firm pays higher salaries to men than women then that firm is likely guilty of discrimination. But I rather suspect that Smith, a women's college that has a female president and provost, doesn't discriminate against female professors. Rather men are more likely than women to go into mathematical fields that have higher market wages. As a result, Smith is forced by the market to pay higher average wages to men than women.