Last night I went to an event at the London Review Bookshop at which Richard Wilkinson and Kate Pickett discussed their book The Spirit Level.

They described their research which seems to show that (among richer nations at least) most indicators of health and mental health (life expectancy, incidence of mental illness, teenage pregnancy) as well as violence and crime are correlated not with the overall wealth of the country but with the degree of inequality within it.

I'll review the book when I've read it.