Our article in Prospect magazine

Submitted by Kathryn Busby on 10 August 2010

Article in Prospect magazine

Professors Richard Wilkinson and Kate Pickett

Published by Prospect on 10 August 2010

Our book The Spirit Level shows first, that many problems that are more common lower down the social ladder are worse in societies with bigger income differences, and second, that almost everyone would benefit from reduced inequality. To some these seem impossible notions. Writing in the August 2010 edition of Prospect, Matthew Sinclair from the Taxpayers Alliance claimed our research was "simply untrue." 

Sinclair believes he has spotted statistical sleights of hand that hundreds of our fellow academics reviewing our work for dozens of journals have failed to detect. Decades of peer-reviewed epidemiological research, funded by research councils, have, he imagines, been torn to shreds by Christopher Snowdon, described as a “public health researcher”. But Snowdon has no public health qualifications and appears never to have published research in a peer reviewed academic journal. His main contribution to public health is a diatribe against tobacco control and a denial of the ill effects of second-hand smoke.

The Spirit Level shows that more equal societies enjoy better physical and mental health, lower homicide rates, fewer drug problems, fewer teenage births, higher maths and literacy scores, higher standards of child wellbeing, less bullying in schools, lower obesity rates, and fewer people in prison. More equal societies also have a stronger community life and are more cohesive. Over the years, a large number of research papers have shown that one or other of these problems are more common in more unequal societies. We could simply have picked out the most dramatic examples from other people’s work to show in our book. But, to show the remarkably consistent tendency for problems associated with relative deprivation to be more common in more unequal societies, we wanted to show it occurs in one problem after another even when using exactly the same group of countries and the same measures of inequality.

To rule out the effects of differences in material living standards, we looked only at the very richest societies where – in contrast to poorer countries – there is no longer any correlation between national income per person and outcomes such as health, happiness or wellbeing. Identifying the 50 richest countries according to the World Bank’s preferred method for classifying countries into High, Medium and Low income categories, we also removed countries with fewer than 3 million people (to avoid tax havens), and those lacking internationally comparable income distribution data.

This left us with 23 rich market societies. We took our data from the best sources, such as WHO, the UN and the World Bank. To double-check our findings, we then repeated our analyses for the 50 US states, to see if more unequal states showed the same consistent tendency to have more of these health and social problems. In almost 30 different cross-national analyses, we show the same tendency for one problem after another to be significantly worse in societies with bigger income differences.

Inevitably the choice of problems we examined was partly decided by the availability of internationally comparable data, but the overwhelming consensus is that we were able to include the most serious of the problems which congregate at the bottom of society. But to safeguard against the criticism that we picked problems to suit our argument, we showed (initially in a paper published by the British Medical Journal) that the UNICEF Index of Child Wellbeing is also strongly related to inequality. It has 40 components covering every aspect of child wellbeing, which we had no hand in selecting.

We made an absolute rule never to pick and choose data points to suit our argument. This is in sharp contrast to our critics who, with the sole purpose of reducing the statistical significance of each association, want to exclude some countries or US states here, others there or, failing that, to alter the picture by adding in poorer countries. However, suppose that, despite not accepting their rationale, we allowed all our critics’ ad hoc exclusions together – the Scandinavian countries, USA, Japan, southern states of the USA? Even then, our index combining ten key health and social problems remains strongly related to inequality. So even if the links between inequality and individual problems can be made to disappear by dubious practices, they are actually extremely robust.

Our critics also ignore the fact that these relationships have been widely demonstrated by other researchers. For example, as early as 1993 in the Criminal Justice Review, Hsieh and Pugh reviewed 34 studies of income inequality and violent crime and found a consistent correlation between the two – the authors estimated that it would need 58 new studies which found no effect in order to overturn this result. But studies since then have continued to confirm the link.

Similarly, our review of research published in peer reviewed journals found that the tendency for health to be worse in more unequal societies has been demonstrated well over a hundred times (see: Social Science and Medicine 2006). Faced with research papers showing that this pattern is repeated among the regions of Russia, the provinces of China, the counties of Chile, or rich and poor countries together, we wonder what regions, provinces, counties or developing countries our critics would find excuses to exclude to deny a relationship?

Again in contrast to our critics, we offer a coherent theory of why so many health and social problems are linked to greater inequality. Rather than being caused directly by material conditions or being simply a reflection of selective social mobility sorting the resilient from the vulnerable, the link with income inequality suggests that the problems associated with social status are responses to the stresses of social status differentiation itself.

We remain puzzled by the stance the Tax Payers Alliance has taken to our work. As we point out, greater equality need not depend on high taxation. The state of New Hampshire has amongst the lowest taxes in the USA. It has no income tax or state sales tax but, like other more equal states, it does well in terms of a host of social measures including rates of infant mortality, homicides, teenage pregnancies, imprisonment, levels of trust and children’s school performance. It stands as an example of the benefits of a fairer and more equal society.