Two interesting news were reported this week. Forbes Magazine reported that the net worth of the wealthiest 400 Americans increased by 13 percent compared to last year. This is hardly surprising, since the magnitude of the top fortunes have been growing rapidly over the last 30 years.

The second news, reported by New York Times’ Sabrina Tavernise, is “Life Spans Shrink for Least-Educated Whites in the U.S.” The real shocker is the magnitude of the shrinkage: between 1990 and 2008 the life expectancy of white women without a high school diploma declined by five years. At the same time white men who dropped out of high school lost three years of life. And we are not talking about a tiny group – Americans without a high school diploma constitute 12 percent of the population.

Are these two developments related? As far as I have seen most media reported them separately without making a connection. Tavernise, for example, discusses several possible explanations, but never comes to a conclusion. As she reports, “researchers offered theories for the drop in life expectancy, but cautioned that none could fully explain it.”

There are a multitude of possible proximate mechanisms explaining this drop in life expectancy (and Tavernise discusses many of them: more risky behaviors, overdoses from prescription drugs, smoking, less access to health care). But I would argue that the ultimate mechanism has to do with the growth of inequality in America over the last 30 years.

So the two news stories are actually related. Incidentally, Tavernise never mentions the word ‘inequality.’

Inequality can take many forms. One is ‘categorical inequality,’ such as the discrimination on the basis of race or gender. This kind of inequality has been declining in the U.S. (although there is still much room for improvement). But at the same time different kinds of inequality, ‘quantitative’ rather than categorical, have been increasing.

Read more at Social Evolution Forum.