May I remind you that the rises in income inequality that have taken place in so many of the rich, developed countries has not been driven by changes in education systems. The runaway incomes at the top are a quite separate phenomenon, and that's what has driven the widening income differences. Of course education, particularly early education, is important. But it's a different subject.
Income inequality matters for its own sake. If you look at the major changes in inequality in the 20th century, you get high inequality until sometime about 1930, and then it slides all the way through the thirties, forties, fifties, sixties, seventies, and then you get the modern rise of inequality. That is, as Paul Krugman says, driven by politics. We know that the newer liberal economics that came in at the beginning of that rise is crucial.