If you fancy yourself clear-thinking, then you ought to be very careful with the word 'over-represent' and its opposite. These words are ambiguous as between normative and non-normative readings. It is just a fact that there are proportionately more Asians than blacks in the elite high schools of New York City. But it doesn't follow that this state of affairs is one that ought not be, or that it would be better if there were proportional representation. So don't say that the Asians are 'over-represented.' For then you are trading in confusion. You are blurring the distinction between the statement of a fact and the expression of a value judgment.
Consider the sports analogy. Asians are 'under-represented' on basketball teams. That is a fact. But it doesn't follow that this state of affairs is one that ought not be, or that it would be better if there were proportional representation. Enforced proportional representation would adversely affect the quality of basketball games.
Women are 'over-represented' among massage therapists and realtors in that there are more of them than men in those professions. Is that bad? Of course not. It is just a fact. And one easily explained. Women are better than men at the sorts of negotiations that real estate transactions involve. For an excellent discussion of such generic statements see my cleverly named Generic Statements. It has been my experience that liberals have a heard time wrapping their heads around generic statements. They also have a hard time grasping the logic of stereotypes.
As for the massage therapists, it is easy to understand why most of them are women. Men love to have their naked bodies rubbed in dark rooms by women. Women do not love to have their naked bodies rubbed in dark rooms by men. Capisce? By the way, both of the preceding statements are themselves generic.
If you say that women are 'under-represented' in philosophy, are you reporting a fact or reporting a fact plus bemoaning said fact? It is true that there are fewer women than men in philosophy. But it doesn't follow that this is a state of affairs that needs correction. There are perfectly non-nefarious explanations of the fact.
'Over-represent' and 'under-represent' are words best avoided because they paper over illicit inferential slides from the factual to the normative/evaluative. Is that why liberals like them?