The pain of inequity appears to have a tangible effect on a country's health.
That's because rising income inequality has caused some people to die earlier, leading to more total deaths in the United States, according to a new study by Hui Zheng, a sociology professor at Ohio State University.
A percentage point increase in the Gini coefficient, a measure of income inequality, more than doubles the odds of death over the next 12 years. In America, the Gini coefficient has risen by 6.6 percentage points since 1980.
"This finding is striking and it supports the argument that income inequality is a public health concern," Zheng said in a release accompanying the findings.
Indeed, the study adds weight to a 2008 Congressional Budget Office report that found the life-expectancy gap between the rich and poor in the United States has grown alongside spiking income inequality since the 1980s.
The boost in deaths likely hurts the poor more than the wealthy precisely because the rich are largely shielded from the public health dangers of income inequality. An extra $10,000 of family income reduces the odds of death by 16 percent, according to the study. Each year of additional education also led to a 3 percent decrease in the odds of death. Having a job reduces the odds of death by 37 percent.
Past studies cited by Zheng have found that income inequality often poses a danger to public health. A larger wealth gap, for example, makes the rich care less about their communities, so they invest less in public goods such as health care, according to one study cited.
The phenomenon doesn't appear specific to the United States. A recent study in the United Kingdom found the rich live longer than the poor by as much as three years on average.