Nick Cohen and Gillian Tett are both worried about declining trust. Nick fears that "a referendum that was meant to let "the people take control" and "restore trust" will have achieved the opposite." And Gillian writes:

we are moving from a system based around vertical axes of trust, where we trust people who seem to have more authority than we do, to one predicated on horizontal axes of trust: we take advice from our peer group.

There's something important missing here - inequality. We have good evidence that increasing inequality leads to lower trust. As Mitchell Brown and Eric Uslaner write (pdf):

Declines in trust stem from economic inequality. As economic inequality increases, people feel that they have less in common with others, and therefore trust less.

The idea here is simple. As Alberto Alesina and Eliana La Ferrara say, "individuals trust those more similar to themselves". In unequal societies, however, rulers and experts are less similar to laymen, and so are less trusted*. This might be magnified by the outgroup homogeneity bias. Readers of this blog might be well aware of the big differences between, say, Ed Miliband and David Cameron, but to someone living in poverty in Hull they are both posh Oxford types.

As we're seeing, this distrust has important effects upon political culture. For one thing, as Gillian says, it leads to a groupthink in which every tribe builds its own reality. Also, it erodes representative democracy. One reason why we had a referendum on the EU was that many voters didn't trust MPs to take the decision for them. There's a third thing, pointed out by James Coleman:

There seems to be extensive evidence that the rise of a charismatic leader...is likely to occur in a period when trust or legitimacy has been extensively withdrawn from existing social institutions. (Foundations of Social Theory p196)

The popularity of Nigel Farage fits this pattern**: we should worry that the gap left by his retirement will be filled by someone even worse.

All these processes are exacerbated by a weak economy, because as Ben Friedman has shown, economic stagnation fuels intolerance and closed-mindedness.

The point here is a simple one. The costs of inequality are not merely economic or social ones. They are also political: inequality leads to poorer political decision-making.

* The inequality that matters in this context might be more complex than simple Gini coefficients, being some mix of immobility, top income shares and an atmosphere of social distance and unequal respect.

** It's worth asking how a privately-educated commodities trader who doesn't listen to music, watch TV or read should have become regarded as a man of the people.

Another thing: you might object that the vote to leave the EU was the right one. However, in a good polity, the right decisions get made for the right reasons. This cannot be said of a campaign which was dominated by lies, racism and crass anti-intellectualism.