When Richard Wilkinson retired as professor of social epidemiology at the University of Nottingham in 2008, it might have seemed that his platform to explain the effects of inequality on society had been diminished. On the contrary, The Spirit Level: why more equal societies almost always do better, the book he has recently written with fellow academic Kate Pickett, has captured the public imagination in a most unexpected fashion.
As he explained it to me, the central premise of The Spirit Level is that 'more unequal societies - with bigger differences between rich and poor - have a greater incidence of a whole range of health and social problems, from violence to obesity to mental illness.
'The more unequal a society becomes, the more common these problems become. Crucially, even the better off do less well in a more unequal society, as they are unable to insulate themselves from the wider consequences. Colleagues at Harvard described inequality as a social "pollutant", because its damaging effects spread to almost everyone, right across the social hierarchy. The biggest effects are at the bottom of the social ladder, but even at the top people do better in more equal societies.'
It is not the first time that Professor Wilkinson has argued such views from the epidemiological evidence. In The Impact of Inequality and a number of other books in previous decades, he has made the case that relative inequality has a vital and often overlooked influence on overall societal health and wellbeing. The impact of the recession, however, and the desire for explanation and solutions, has led to this latest work becoming much more popular than his previous attempts.
Inequality, Wilkinson explains, increases status competition. 'Many societal problems, including severe ones such as violent crime, are caused by a sense of being disrespected and looked down on. It shouldn't really come as a surprise that societies in which wealth and status are seen as the priorities, rather than public service and community, should have far greater problems across a whole range of areas.'
A new framework
The Spirit Level has attracted so much interest largely because it is an accessible summary that fits many hundreds of academic studies into a new framework, showing the effect of inequality on wider society. Rather than relying on anecdote or assertion, it marshals hard data from decades of research.
Much of this is the authors' own, but they also draw on many other people's work, including books such as Bowling Alone, Robert Putnam's book on the US's declining 'social capital'. Wilkinson points out that the rise and fall of 'social capital' follows first the narrowing and then the widening of income differences within developed societies. 'Put simply,' he says, 'inequality has psycho-social effects. In a more unequal society people are more violent, less public spirited, less likely to trust each other or to be involved in community life.'
As well as studying the incidences of health and social problems in countries with different levels of income equality, The Spirit Level also compares the data for all 50 US states. Here, too, the correlation between equality and social breakdown is compelling. It appears that, even within an unequal country such as the US, states with greater equality experience fewer social problems than those with more economic inequality.
Wilkinson does add a caveat to this, commenting that 'deprived neighbourhoods do not have bad health because of the inequality within them, but because they are deprived in relation to the wider society, so income inequality has to be measured across large areas.' Nonetheless, policy measures taken to increase equality across an area the size of a city, for example, will have a positive effect on social problems - as Wilkinson and Pickett will argue in a forthcoming report for the London Sustainable Development Commission.
While the large majority of social issues studied by the two authors became more prevalent as inequality increased, this was not the case for every problem. The statistics show that suicide, for example, actually occurs at a higher rate in more equal societies.
'Very often, where suicide rates are high, violence is low, and vice versa,' explains Wilkinson. 'I think that there is probably some truth to the cliché that violence either goes in, against yourself, or out, against other people.'
'In a well known paper on health in Harlem,' he continues, 'it was found that death rates for most ages were higher than in Bangladesh. The only cause of death that was not more common in Harlem than the rest of the US was suicide. It's a matter of whether you blame your problems on yourself, or on other people - and in societies with more community responsibility, it tends to be the former.'
Many ways of increasing equality
Wilkinson is forthright about the fact that the rise of inequality in the UK was driven by politics and that it is possible to narrow income differences again. 'Clearly, although Thatcher was happy to see inequality increase, she did not intend to increase rates of obesity, teenage birth rates, drug problems, mental illness or violent crime - but these are all the unintended consequences of the inequality she created,' he explains.
'Fortunately, there are many ways of increasing equality. Although Japan and Sweden are among the most equal countries, they get their equality in very different ways. Japan is more equal because their earnings differences are smaller even before taxes and benefits, so they do rather little redistribution. Sweden, in contrast, starts off with big earnings differences and then redistributes.' There are, therefore, small government routes and big government routes to greater equality.
The solution for the UK, Wilkinson argues, is both redistribution and greater 'economic democracy' - the ability of ordinary people and their communities to have greater control over the institutions in which they work. 'To reduce earnings differences at source, we need more cooperatives, mutuals, friendly societies and employee ownership,' he says. 'As well as bringing pay differences directly or indirectly under more democratic control, employee ownership redistributes wealth and can change a company from a piece of property into a community.'
As an epidemiologist, Wilkinson is unwilling to give a definite opinion on the question of whether there are limits beyond which greater equality is desirable. 'I'm not absolutely sure, and as academics, we are constrained by our data. We can see that equality is important all the way to the most equal of the developed countries - whether going on beyond that would be beneficial, we don't know. We've seen no sign that it wouldn't be. And it is interesting that Cuba's health statistics are almost as good as the US, despite much smaller health expenditure.'
As you might expect, the phenomenon of a rigorously researched book pointing to the disaster of inequality has not gone uncriticised. Recently, in a discussion of inequality on Radio 4's Moral Maze, Michael Portillo said that even if we accept that inequality has the damaging social consequences described in The Spirit Level, he thought that economic progress required the innovation and creativity that he believed depended on financial rewards and incentives.
Thinking about this afterwards, Wilkinson and Pickett realised that the number of patents granted per head of population would be a good measure of innovation and creativity. But rather than finding that more unequal societies had greater innovative success, they found the opposite: more equal societies have a greater number of patents per head. 'It's quite simple - more unequal societies waste the talents of their populations by making millions of people feel second rate and failures,' he explains.
In order to make the book's findings better known, the authors set up the Equality Trust, which has since moved into campaigning for policy changes in the UK. It is planning a campaign for greater equality in the lead up to the general election in 2010. Wilkinson is optimistic, despite the enormous challenges faced by such an agenda. 'From people's responses when they see the evidence, I've come to feel that the world is actually full of closet egalitarians who recognise the hollowness of consumerism and status competition. We know that in future the real quality of life will depend on our ability to shift from the pursuit of economic growth and raising material standards to using greater equality to improve the quality of the social environment.
'By improving the quality of social relations in societies, greater equality reduces consumerism and status competition and makes it easier to achieve sustainablity. If we can present people with a different conception of the future, a future in which environmental and social problems are soluble, there could be very rapid changes in public attitudes.'
The Spirit Level is published by Allen Lane
Matt Sellwood is the Green Party parliamentary candidate for Hackney North and Stoke Newington