It’s Sunday, typically a day of rest for most. But if you’re reading this article from your office—you’re not alone.

A new paper by economists Dan Hamermesh and Elena Stancanelli found that Americans not only work longer hours, but they are more likely to work late at night and on weekends as well.

They found that on a typical weeknight, a quarter of American workers did some kind of work between 10 p.m. and 6 a.m. That’s a lot, compared with about seven percent in France and the Netherlands. The U.K. is closest to the U.S. on this measure, where 19 percent work during night hours. On the weekends, one in three workers in the U.S. were on the job, compared to one in five in France, Germany, and the Netherlands.

All of this adds up: According to the OECD, the U.S. leads the way in average annual work hours at 1,790—200 more hours than France, the Netherlands, and Denmark. That works out to about 35 hours a week, but a recent Gallup poll found the average to be much higher than that—at 47 hours weekly. And perhaps that’s not surprising, when 55 percent of college grads report that they get their sense of identity from their work.

Technology is increasingly making work more accessible from home. But what's so wrong with working so much? The economists note two setbacks to our hardworking culture: less of a social life, and possibly worse health conditions. Hamermesh, for one, says it's not worth it: "We have driven ourselves to the point where we work more and get less and less for it."