"Epidemiology is not a hot topic outside specialized circles. It does not feature in coffeetable books or paperbacks. Its insights never inform electoral campaigns. Wilkinson and Pickett's book The Spirit Level is a standout exception. A bestseller in its field, it has been cited – not always in context - by both the UK's current Conservative PM David Cameron and the new opposition Labour leader Ed Miliband. It has been embroiled in controversy and endless debates in the United Kingdom and beyond since its release.
The Spirit Level refers both to labour and to one of the most engaging movements of England's 17th century revolution: the Levellers and the radical democratic demands they embodied.
The authors discuss the relationship between rising income inequality and a set of indicators that reflect the quality of life in developed capitalist countries. They review the existing data across a wide range of fields - infant mortality, obesity, violent deaths, imprisonment rates, etc. – and use studies that are valid and homogeneous enough to enables comparison.
They are clear on the fact that quality of life in a society is dictated not by wealth creation as reflected in gross national product, but much more directly by levels of income inequality. The 23 countries examined can be ranked by scale of income inequality. The least unequal countries are Japan, Finland, Norway and Sweden, where the incomes of the richest 20% are three to four times higher than the poorest 20%. At the other end of the spectrum are Singapore, the United States, Portugal, the United Kingdom and Australia with differences ranging from 7 to 10. Most of the EU countries fall between the two extremes (5.2 for Germany, 5.6 for France, 6.7 for Italy). Looking at the quality of life performance of the same countries, it is clear that basically, the more unequal the incomes, the worse the outcomes are for society: illiteracy, infant mortality and prison population rates all rise. The same trend is found for mental illness, teenage pregnancies, cardiovascular diseases, drug and prescription medicine abuse, low social mobility and educational failure rates. The pattern is similar for the United States. Quality of life is observably better in those of the 50 states where income is least unequally distributed. With comparable per capita levels of wealth but more equality, life is much better in Minnesota, Vermont and Iowa than in California, Georgia or Texas.
While it contributes no new data, what The Spirit Level do has going for it is to provide an accessible summary of data generally found piecemeal across specialized studies. The first part of the book shows that there is an overall consistency in the way societies work and that income inequality is almost always associated with a wide range of seemingly unconnected negative developments. The inference is that sector-specific policies are likely to be less effective than an across the- board policy to close equality gaps.
In part two, the authors outline a model that explains the link between inequalities and widespread social unease. They point to the role of stress, taking an approach that blends psychology, anthropology, medicine and social relations. The authors contrast the hierarchical dominant-dominated trend with the desire for communication, cooperation and feelings of gratitude and mutual support, and show how these tendencies to come together in partnerships of equals engender mutual trust, reduce psychological stresses and benefit both individual health and life in society. The explanations, while often compelling, nevertheless remain partial. Its brevity and urge to portray complex social relations as a sort of logic diagram means that the book sometimes underestimates the specific way in which capitalism ties into the social relations that came before it. Social and cultural history - be it slavery in the United States, the Lutheran Reformation in the Scandinavian countries or the links between the labour movement and social democracy in Western Europe - takes second place and is reduced to a backcloth of almost passing interest.
Political perspectives take up a third section of the book. The argument that it is more important to combat inequalities than to increase the production of material wealth flows logically from the analyses. Readers may, however, be surprised by the gap between the radical findings and the extremely cautious policy options proposed. The policy advocated is "a continuous stream of small changes in a consistent direction". Producers' cooperatives are given a big role in taking the economy and society forward. The authors seem to feel that a policy based on the clear force of the figures would be able to persuade the "haves" of the need for a society free of inequalities. The pragmatic arguments deployed for that do not fully take into account the complexity of the issues: it is not just about income, but also ownership and the power that confers on the lives of others. There needs to be a more specifically political debate on the faith that we are on an irreversible trend towards more equality. Relying on statistical and epidemiological data alone is not enough. There is no skimping a discussion on the goals of, alliances for and likely obstacles to societal change. — Laurent Vogel"

Support: Digital;Paper