In an interview, Richard Wilkinson says

I think people are extremely sensitive to status differentiation and to being looked down on, or disrespected, and those often seem to be the triggers to violence. We quote an American prison psychiatrist who goes so far as to say he’s never seen a serious act of violence that wasn’t provoked by loss of face or humiliation, and so on. And in more unequal societies, status matters even more. People judge each other more by status. There’s more insecurity. And people at the bottom are more often excluded from the markers of status, the jobs and housing and cars, so they become even more touchy about how they’re seen.

Wilkinson likes Sweden, where there is less inequality.

Why is the nation-state the relevant unit for measuring inequality? Sweden has 9.2 million people, and we have 300 million, so we are bound to have more inequality, particularly by the sorts of measures Wilkinson uses.

Instead of an international comparison, why not compare, say, Indiana with Sweden, or Indiana with New York City? Is Indiana much more unequal than Sweden? I assume inequality is less in Indiana than in New York City. How does that affect happiness in the two places?

I raise this point because I think the only way we could have a more egalitarian society would be if we broke the country up into smaller units, and we measured equality within the unit. Otherwise, the amount of political power it would take to get rid of the economic inequalities among 300 million people spread over such a large area would be frightening. It might be equally difficult to produce equality in Europe, if one defines equality by looking at the bottom of the ladder in, say, Croatia, with the top of the ladder in, say, Germany.