But they're not "counteracted" at all.
They are for the metric of median wages.
There's a similar situation with PISA scores: American students of all races are the highest or second highest scorers of that race. The average American PISA score is mediocre, though, because the US's racial balance is not, say, Shanghai's or Finland's racial balance.
I'm curious by what steps of reasoning do you pick out the hypothesis of "racial balance" rather than, say, "income inequality"?
ETA: The table linked by Landsburg has been called into serious question by Evan Soltas [H.T. CronoDAS]. I edited the post to leave only the table to provide context for the comment discussion of its status.
Economist Steve Landsburg has a post [H.T. David Henderson] about the supposed stagnation of median wages in the United States in recent decades. In the linked table median wages have risen for: