The Spirit Level: Why More Equal Societies Almost Always Do Better by well known public health researchers Robert Wilkinson and Kate Pickett is reviewed by political scientist David Runciman in the London Review of Books article How messy it all is:
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. They do worse even if they are richer overall, so that per capita GDP turns out to be much less significant for general wellbeing than the size of the gap between the richest and poorest 20 per cent of the population (the basic measure of inequality the authors use). 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. In graph after graph measuring various welfare functions, the authors show that the best predictor of how countries will rank is not the differences in wealth between them (which would result in the US coming top, with the Scandinavian countries and the UK not too far behind, and poorer European nations like Greece and Portugal bringing up the rear) but the differences in wealth within them (so the US, as the most unequal society, comes last on many measures, followed by Portugal and the UK, both places where the gap between rich and poor is relatively large, with Spain and Greece somewhere in the middle, and the Scandinavian countries invariably out in front, along with Japan). Just as significantly, this pattern holds inside the US as well, where states with high levels of income inequality also tend to have the greatest social problems. It is true that some of the most unequal American states are also among the poorest (Mississippi, Louisiana, West Virginia), so you might expect things to go worse there. But some unequal states are also rich (California), whereas some fairly equal ones are also quite poor (Utah). Only a few (New Hampshire, Wyoming) score well on both counts. What the graphs show are the unequal states tending to cluster together regardless of income, so that California usually finds itself alongside Mississippi scoring badly, while New Hampshire and Utah both do consistently well. Income inequality, not income per se, appears to be the key. As a result, the authors are able to draw a clear conclusion: ‘The evidence shows that even small decreases in inequality, already a reality in some rich market democracies, make a very important difference to the quality of life.’ Achieving these decreases should be the central goal of our politics, precisely because we can be confident that it works. This is absolutely not, they insist, a ‘utopian dream’.
Why then, given all this – the concise argument, the weight of the evidence, the unmistakable practical purpose of the authors – does the book still feel oddly utopian? Part of the problem, I think, is that the argument is not as straightforward as its authors would like. Despite their obvious sense of conviction, and maybe even because of it, they fudge the central issue at crucial moments, whereas at others, perhaps in order to compensate, they overstate their case, which only makes things worse. To start with the fudge. Is the basic claim here that in more equal societies almost everyone does better, or is it simply that everyone does better on average? …
Robert Wilkinson and Kate Pickett also have a review article Income Inequality and Social Dysfunction in the Annual Review of Sociology (2009 35:493-511) that examines the support for various hypotheses of the relationship between inequality and social dysfunction.