A new report confirms what we already knew: the rich live longer than the poor. The study looked at people in the United States who were in their fifties in 1991, and found that three-quarters of the richest among them are still alive today, compared to less than half of the poorest.

This isn’t really news, though it’s good to firm up the stats. Lots of other studies have concluded the same thing. A 2016 study found that the richest 1 percent of US women live more than a decade longer than the poorest 1 percent. And the gap is even wider for men. Bernie Sanders likes to share a statistic that life expectancy for men in West Virginia’s McDowell County, the poorest in the nation, is sixty-five years, while in Virginia’s Fairfax County, one of the richest, it’s eighty-two years.

The findings aren’t up for debate. The question that remains is: Why? How come the wealthy get to walk the earth longer than the poor? Unsurprisingly, some terrible ideas have been floated to explain the trend. In 2004, for example, some researchers claimed that rich people live longer because they are smarter and therefore have superior health literacy, which means they take care of their bodies better. In this view, the deficient poor are to blame for their struggles, both physical and economic. If only they were more intelligent, they would know how to make money, and also that smoking and fast food are bad for them.