Fat cats sleep better. Flickr user Martin Cathrae (CC).

Mo' money, mo' sleep.

That's the takeaway from a fascinating slice of data the Centers for Disease Control and Prevention last week looking at sleep levels by income group. Crunching numbers from the 2013 National Health Interview Survey, CDC researchers found that the relationship between income and sleep is linear and positive.


Just under two-thirds of people living below the federal poverty line -- $23,550 for a family of four in 2013 -- reported getting more than 6 hours of sleep per night that year. But nearly three-quarters of people with incomes at 400% of the poverty level -- $94,200 for that same family of four -- reported getting that much sleep.

The CDC has called sleep deficiency a "public health epidemic," and with good reason: "Persons experiencing sleep insufficiency are also more likely to suffer from chronic diseases such as hypertension, diabetes, depression, and obesity, as well as from cancer, increased mortality, and reduced quality of life and productivity," the Centers wrote last year. And drowsy driving causes 80,000 traffic accidents each year, 1,000 of which are fatal.

The new CDC data illustrate how these burdens -- like so many of our public health problems -- fall disproportionately on the poor. The popular perception -- particularly in the upper echelons of the income distribution -- is that "the poor have it easy." But these numbers add to the already large body of evidence showing that the very opposite is true.

One reason lower-income Americans aren't sleeping as much? Many of them are holding down multiple jobs to make ends meet. A study released last year found that so-called "short sleepers" -- those who get fewer than 6 hours per night -- were mostly trading work hours for sleep hours. It also found that multiple job holders were "were 61 percent more likely than others to report sleeping 6 hours or less on weekdays."