The answer, as with most things in education, is money. Vox recently reported on a study of a large, diverse school district that changed the way it tested students for admission to their Gifted and Talented (G&T) program. As with most districts, this one waited for teachers to refer first or second grade students, and then these students were admitted based on an IQ test and other measures from district psychologists. Teachers, however, referred a larger number of white, middle and upper class students. When the district changed their approach and screened all students (regardless of teacher referral) with a shorter test, then there was a massive increase in the number of minority students admitted to the G&T program. Great, until the recession hit, the budget was cut and the universal screening program and the additional testing it required were cut from the budget. Now, the levels of minority students in the G&T program are back to where they were before the universal screening was implemented.
The biggest takeaway is that doing write by students just costs money. There is certainly an indication that there is work to be done getting teachers to recognize gifted minority students since if they were referred at a higher level then more would be admitted. However, even if the teachers referred more, if there aren't enough psychologists to test them (and in a diverse district the psychologists are also likely doing a lot of evaluation for Special Education as well) then it doesn't matter who is referred. I am also worried about the budget means for those students actually in the G&T programs. Is there enough money to give them a challenging program? Is the district stuck with trying to meet the needs of its diverse students (providing for students with Disabilities, providing for English Language Learners) and has nothing left for Gifted Students? It's worrying and my heart goes out to all of the teachers and parents of students for whom there is just not enough to go around.