Lighter, I think you're perhaps unconsciously misunderstanding the English habit of making modest claims. The figures show more than a tendency; in countries with more level wage structures - places like Japan and Sweden, for instance - the outcomes are better for virtually every one of the social questions studied (jail numbers, education, safe childbirth, health, etc) than in places with a bigger gap between richest and poorest.
What can we do about it? Perhaps as individuals, we can avoid buying from exploitative companies. We can change our attitude for money, so that we don't regard a high wage as a signifier of ability, virtue, intelligence etc (probably not much of a leap for most people here, who are talented musicians and not highly paid). What do *you* think we can do?