Robin Hood index shows mortality in US related to inequality of income

This graph (from Kennedy et al 1996) shows how mortality is related to inequality among US states. The measure of inequality used, the Robin Hood Index, is the proportion of money needed to be transferred from the rich to the poor to achieve equality. Kennedy, et al, write:

'Variations between states in the inequality of income were associated with increased mortality from several causes. The size of the gap between the wealthy and less well off--as distinct from the absolute standard of living enjoyed by the poor--seems to matter in its own right. The findings suggest that policies that deal with the growing inequities in income distribution may have an important impact on the health of the population.

'Key messages: The size of the gap between the wealthy and less well off--as distinct from the absolute standard of living enjoyed by the poor--seems to be related to mortality

'Policies that deal with the growing inequities in income distribution may have a considerable impact on the health of the population'

Source: Kennedy BP, Kawachi I, Prothrow-Stith D. Income distribution and mortality: cross sectional ecological study of the Robin Hood index in the United States. British Medical Journal 1996; 312: 1004-7. The full paper can be read at http://www.bmj.com/cgi/content/full/312/7037/1004.