Americans, you may have heard, are the workaholics of the developed world. While there are a few nations that beat the United States in terms of number of hours logged at the office--Korea and Mexico are two noteworthy examples--if you compare us with almost any European, U.S. professionals just can't seem to turn off their gadgets and go home.

The Netherlands? Germany? Denmark? France? The U.K.? You name any European country and the answer will be the same--American workers put in more hours than workers there do. Now, a new NBER working paper expands on this well-established fact, not just confirming that Americans put in more time at work, but also showing exactly when they're racking up those hours.

A nation of workaholics

Not too surprisingly, it turns out that putting in all those hours requires us to work some pretty unusual hours as well. Compared with most other developed countries, we're far more likely to work late at night (defined here as after 10 p.m.) and on weekends. While this is pretty logical given our long workweeks, the extent to which we do this might surprise you--on average, a quarter of us work late at night on any given day.

As a write-up of the NBER paper in Quartz explains, this difference between the U.S. and other nations is only growing larger. Other nations (it may or may not burn you to know) have actually been working less recently. America? Not so much.

"In recent decades, work hours have actually gone down around the world. Many countries adopted controls or limitations on the workday, and technology helped reduce hours. Comparing annual work hours in 1979 and 2012, America's overall work hours declined slightly, but saw less of a drop than any country except for Sweden, where hours increased," reports Max Nisen.

Should we be concerned?

These facts are interesting, of course (as is the finding that Americans also often exaggerate how much they work), but probably more important is the question, should we be concerned? Decades of research show that working more than 40 hours a week is unsustainable and severely dents productivity per hour, and neuroscientists and others warn that failing to give your brain adequate time to rest and recuperate is a recipe for disaster (which you might guess that many people have grasped for themselves, given the current mania for "mindfulness").

On the other hand, working weird hours allows business owners and others to take advantage of international opportunities despite time zone differences (I live seven time zones away from HQ, so can personally attest to this, for instance), while some surveys show that the always-switched-on are actually more satisfied with their lives than those who shut down their computers at a reasonable hour each day. Meanwhile, you can find personal essays attesting to the fact that, for some, being always tethered to your gadgets is a way to be more engaged with family life, not less.

What's your take on these findings? Are our strange work hours a simple reflection of tech-enabled flexibility and Americans' passion for their jobs, or a sign that bosses' sanity and workers' rights really need to be better protected?