Many articles have been published discussing whether changes in economic inequality lead to changes in mortality rates, yet, no consensus has emerged. One major reason has been the paucity of reliable historical data on income inequality. As a result, most studies have examined the relationship between inequality and mortality at a single point in time.
Because income inequality and mortality are likely to have common causes that cannot all be measured, the cross-sectional relationship between inequality and mortality is unlikely to provide an unbiased estimate of how changes in income inequality affect mortality.
This paper investigates this issue using a new source of data on economic inequality; the share of personal income received by the richest 10 percent of adults in some countries. These countries are Australia, Canada, France, Germany, Ireland, the Netherlands, New Zealand, Spain, Sweden, Switzerland, the UK, and the US.
Previous results of similar researches have concluded that although there are plausible reasons for anticipating a relationship between inequality and mortality, the empirical evidence for such a relationship is weak.
Some of the results of the paper include:
there is not much of an agreement about the relationship between income inequality and health
higher GDP is associated with lower mortality, this effect declines as GDP rises
more inequality is associated with higher mortality
the confidence intervals around the estimates are sufficiently tight to make substantively important detrimental effects of inequality on population health unlikely
even a 10 point increase in the income share of the top decile would be unlikely to lower life expectancy by more than 1 year