Want to Make More Money? Get More Sleep.

Sleep may be good for your wallet.

Researchers at Williams College and the University of California-San Diego have found that people tend to earn higher wages in places where the sun sets earlier, allowing for longer sleep.

The scientists looked at sleep and wage information data collected in the American Time Use Survey, administered by the U.S. Bureau of Labor Statistics. “As the sun sets, eastern locations grow dark earlier than western locations, leading residents in more easterly locations go to bed earlier and sleep longer,” the authors note in a working paper summarizing the findings. Just one extra hour of sleep per week translates into a 5% increase in earnings, the researchers found.

Though the exact reasons behind the findings are unclear, scientists think longer sleep duration probably makes people more productive. Put simply, the more rested you are, the more energy you have to work hard and make more money.

The reverse is also true: a lack of sleep costs the U.S. economy $411 billion in productivity losses per year, according to a study published by the research organization RAND Corporation. “Our study shows that the effects from a lack of sleep are massive,” Marco Hafner, a research leader at RAND Europe and co-author of the study says in a statement. “Sleep deprivation not only influences an individual’s health and well-being but has a significant impact on a nation’s economy, with lower productivity levels and a higher mortality risk among workers.”

But there is a solution to this issue. “If those who sleep under six hours a night increase their sleep to between six and seven hours a night, this could add $226.4 billion to the U.S. economy,” Hafner says.

To learn more about how sleep can make you more productive, check out this article.