It is an interesting observation that there is almost no correlation between GNP per capita and life expectancy, amongst developed countries. Within a society, however, we know that personal wealth does play a large role in determining life expectancy. The difference between these two measures is that within a society, GNP per capita is a measure of relative wealth, and is therefore a comparison with others. By using the difference in wealth of the top 20% and bottom 20%, Richard Wilkinson has drawn attention to the strong positive correlation between income inequality and health and social problems. This is shown on the graph below.
This does not simply point out that poverty causes poor health and unhappiness. The evidence actually goes beyond the evidence and suggests that inequality actually leads to worse health outcomes and happiness for the most affluent in society as well as those in relative poverty.
It is thought that higher income inequality causes greater feelings of status insecurity due to comparisons against others in society. The fear of this judgement and a lack of social cohesion increases stress and therefore cortisol levels. This results in increased health and social problems.
Evidence from several studies supports this link between inequality and poor health. For example in the USA in 2001, Lochner et. al found that individuals living in states with greater inequality were at a 12% higher risk of death. In 2009 a study published in the British Medical Journal produced some shocking statistics about the impact that inequality is having on people’s lives in the USA. This study concluded that almost 884,000 deaths per year could be attributed to high inequality, and that this number would be prevented if the Gini coefficient value could be reduced to 0.3 (the average for OECD countries), from its value of 0.357. This is one third of deaths in the USA!
Supporting this, a 2009 BMJ meta-analysis by Kondo et al, found an 8% higher mortality risk per 0.05 increase in the Gini coefficient value.
There is also evidence to suggest that income inequality correlates with lower happiness in societies. For example, a 2011 study carried out in the university of Virginia found that from 1972 to 2008, people in America were happiest in years when income inequality was lower.
The 2015 World Happiness Report found that three quarters of differences in happiness between all countries is due to 6 factors: GDP per capita, healthy years of life expectancy, social support, trust, freedom and generosity (measured in donations comparative to income). Although this does not specifically highlight income inequality as a factor in happiness, it has been found to be linked to several of these 6 factors. For example, Richard Wilkinson’s research has also found a strong negative correlation between levels of trust in society and income inequality. There is also a strong correlation between income inequality and social immobility which would therefore mean that there was less freedom in more unequal societies. It is also likely that social support may be reduced by inequality as isolation tends to be higher.
The following maps show happiness rankings, and the Gini Coefficient (a measure of income inequality). It can be seen that there is some correlation, especially when considering the worlds happiest countries: Switzerland, Iceland, Denmark, Norway, Canada, Finland, Netherlands, Sweden, which all have fairly low Gini Coefficient values.
-from the Washington Post
Gini Coefficient: (higher being less equal)
-from the Business Insider using World Bank Data
The 2015 World Happiness Report states that ‘happiness is increasingly considered a proper measure of social progress and a goal of public policy’, and there are several organisations, such as Action for Happiness, who encourage people to see the importance of happiness, rather than focusing on financial and status goals.
There is also a large amount of research to suggest that happiness results in a healthier life. For example, Kubzansky’s 2007 paper found that enthusiasm, hopefulness, engagement in life, and emotional balance correlated to a lower risk of coronary heart disease. This is only the tip of the ice burg when it comes to how happiness can be beneficial to your health. It has been suggested that being happy can also reduce the risk of type 2 diabetes, high blood pressure and infection.
Despite happiness having recently gathered interest and making several headlines, there is still a lack of research. An Online Library search reveals around 400,000 results for the word ‘depression’, compared with only 50,000 for ‘happiness’. Now that’s depressing!
WHO – obesity and inequalities
BMJ – income inequality, mortality and self rated health
Harvard School of Public Health