There's a strong whiff of egalitarianism in the air. Britain's bankers are being vilified like the French aristocracy were in 1788; they must be grateful that they face only a mauling in the press. Earlier this year, the Fabian Society gleefully published a poll showing that more than two-thirds of the population believe that "those at the top are failing to pay their fair share towards investment in public services".

Amid the economic gloom, one booming market is for books advocating a more equal society. We've had Robert Peston's Who Runs Britain?, an anatomy of the financial sector, and Polly Toynbee and David Walker's Unjust Rewards Exposing Greed and Inequality in Britain Today. Peter Singer has argued that we have a moral duty to give away a part of our income to help the world's poor and Will Hutton is writing a book about equality and social justice. These endeavours share a hope that the political pendulum is swinging away from the ambivalent attitudes towards wealth of the last three decades; that we are no longer, as Peter Mandelson famously was, "intensely relaxed about people becoming filthy rich".

But the apparently renewed thirst for fairness is ill-defined. People may say the gap between rich and poor is too great, but who counts as "rich" and "poor"? The big income changes in recent years have been at the very top, where a tiny group, the "super-rich", has done extremely well. Among the remaining 99%, the picture is brighter: Labour's redistributive measures have helped the bottom 10% and 20% to keep up with the mainstream. Overall, levels of income inequality have remained steady.

It is a longstanding psychological weakness of many on the left to focus on the earnings of a fraction of high earners rather than the stubborn problems of those nearer the bottom. Crude measures of income distribution are, in any case, secondary indicators of the health of society. Over the next couple of years, the stagnation of private-sector wages will...