The argument of this fascinating and deeply provoking book is easy to summarise: among rich countries, the more unequal ones do worse according to almost every quality of life indicator you can imagine.

The evidence that Wilkinson and Pickett supply to make their case is overwhelming. Whether the test is life expectancy, infant mortality, obesity levels, crime rates, literacy scores, even the amount of rubbish that gets recycled, the more equal the society the better the performance invariably is.