That research is highly dubious, but let's take it at face value. You can send them at a state or city school. But they have a word to say about that choice too. For them, it's not research, it's life. They can't run a controlled experiment with their life. If they go to the city school, and their career tanks, will they ever forgive you? Will they buy your counterfactual that their career would have tanked anyway, even with an elite school diploma framed on their wall?