Just curious, but do you guys come across longtime unemployed minorities on a regular basis and think to yourself, "Gee, I wonder why THAT person doesn't have a really good job"?
Under-representation is determined by looking at the percentage of a population in the workforce or education system and then evaluating whether or not your college or workplace accurate represents that percentage. If your college/workplace has a smaller percentage, then that population is under-represented. You can handle this under-representation is several ways. You can do nothing, you can increase recruitment, consider race as a secondary factor in admissions or you can illegally set quotas among other things.
As you can see, quotas come after determining under-representation - illegally.
"It ain't what they call you, it's what you answer to." - W. C. Fields