It sounds counterintuitive, but the more money people make, the less they sleep, reports The New York Times.

Consider the Great Recession: Americans slept the most during 2009, 2010 and 2011, when unemployment was high. That probably wasn’t because stress was low or attitudes about sleep were healthier — it was because fewer people were working. Or this fact: Retired people sleep more than working age people, even though the biological need for sleep actually declines in old age.