“This image was made in Birkenhead, looking over the Mersey to the ever-developing Liverpool skyline. It is where the A41 finishes at its northern end. For me it’s a metaphor about life with the river acting as a barrier between what exists on one side of the divide and what exists ‘over there’. The fading floral bouquets seem eerily relevant.” People in more equal societies live longer, a smaller proportion of children die in infancy and self- rated health is better.

There are now over 170 studies of income inequality in relation to various aspects of health. Life expectancy, infant mortality, low birth weight and self-rated health have repeatedly been shown to be worse in more unequal societies. Researchers sometimes disagree about the pathways leading from inequality to worse population health. The most consistent interpretation of all the evidence is that the main route hinges on the way inequality makes life more stressful. Chronic stress is known to affect the cardiovascular and immune systems and to lead to more rapid aging. Inequality makes social relations more stressful by increasing status differences and status competition.

These effects are important: Americans living in more equal states live around four years longer than those living in more unequal states.