I've been looking too. It's so hard to find real information on the subject.
But looking at poverty rates and graduation rates it would seem that minorities should be doing much worse. White graduation rates have decreased while their poverty rates have also decreased. Minority graduation rates have increased while their poverty rates have decreased as well.
its very complicated, for example its true students are doing better n some ways but if the people in the high end are doing way way way better, then the gap will persist even if minorities or low income people are doing better
you can slice data in all different ways, for example its also true that whites in the northeast do better than whites in the south or that southeast asians perform a lot worse than asians from china and korea, there are all kinds of gaps everywhere
but imo the gap between blacks and latinos vs whites and asians is significant enough to bring it up in terms of american competitiveness, i think the income gap is also legit, im not disputing that gap