Why aren't voters more concerned about rising inequality? For example, in the UK since the mid-80s, the share of income going to the top 1% has risen from around 8% to over 13%. But during this time the proportion of people agreeing that the government should redistribute income has fallen slightly - with larger falls among younger and working class people.

It could be that this tolerance of inequality reflects an acceptance of neoliberal economics. People are now more inclined to believe that "wealth creators" need high incentives to work hard, and that as they do so we all become richer, so inequality is in our self-interest.

However, new experimental evidence rejects this possibility.

Kris-Stella Trump got subjects to compete in pairs to solve the most anagrams in four minutes. The pairs were randomly divided so that in some pairs the winner got $9 and the loser $1 whilst in others the winner got $6 and the loser $4.However, unknown to the subjects, the competition was rigged so that they always narrowly lost to one of Dr Trump's colleagues. After the game, the losers were asked how they would have divided the prize money. And here's the thing. The losers who got $4 thought it fair a fair split was (on average) $6.15-3.85 but the losers who got just $1 thought a fair split was $7.77-$2.23. In other words, actual inequality shapes our perceptions of fairness. Dr Trump says:

Public ideas of what constitutes fair income inequality are influenced by actual inequality: when inequality changes, opinions regarding what is acceptable change in the same direction.

There are two reasons for this, says Dr Trump. One is the status quo bias; a form of anchoring effect causes us to accept actually existing conditions. The other is the just world effect. We want to believe the world is fair, and if we want to believe something, it's very easy to do so. This is the system justification theory described (pdf) by John Jost and colleagues. There is, they say, "a general psychological tendency to justify and rationalize the status quo" which is "sometimes strongest among those who are most disadvantaged by the social order."

All this corroborates my Marxian prior, that inequality generates cognitive biases - ideology - which help to sustain that inequality.

And this in turn poses a challenge to democratic egalitarians. If this is right, the fact that there's public support for - or at least acquiescence in - inequality is no evidence whatsoever for the justice of that inequality. It might be, therefore, that we cannot achieve justice by democratic methods.