Very few office workers actually work the full eight hours they spend at their desks. There are the coffee breaks and the water cooler chats about whatever Netflix show just premiered, the texts and emails that just have to be dealt with immediately, and, of course, the cat videos that must be watched—and shared around the office. In between, we might get some work done.

But how much slacking off at work is normal? At least half an hour a day, according to a working paper from the National Bureau of Economic Research that lends credence to the notion that long working hours aren't actually very productive. At least, workers report spending 34 minutes of company time a day on non-work activities, on average. When the researchers axed the workers who claimed they really did not deviate from work-related tasks at any point during the day—clearly an unreliable sample population—the average reported messing-around time jumped to 50 minutes a day. So if you're off-task for an hour a day, chances are your coworkers are too.

The data comes from the American Time Use Survey, a diary-based study of how people spend their time, so those self-reported numbers probably aren’t precise. Surely people did not pause to record every minute they spent G-chatting throughout the day. But it’s a decent approximation.

And it’s pretty good fodder for the notion that if you want to get more done, you should actually reduce the hours you spend at work. The study found that the longer people spent at work on a regular basis, the more of that time they spent goofing off.

Some businesses are putting this idea into practice. Recently, some Swedish companies adopted a six-hour workday as a way to give their employees more work-life balance while also increasing the amount of time they spent on-task. Instead of having employees sit at their desks for a full eight hours—during which they’re probably taking breaks to watch cat videos at least part of the time—these companies ask their employees to come in for fewer hours, but stay off social media and put off personal phone calls and emails during that shorter stretch. "It's difficult to concentrate at work for eight hours, but with six hours you can be more focused and get things done more quickly," one business owner explained to the BBC in November.

However, this study found that at a certain point, long hours were, in fact, productive ones. People who worked more than 43 hours a week spent a smaller proportion of their time goofing off than the standard 40-hour-a-week worker. It sort of makes sense—if you already know you have 80 full hours of work to complete in a week, you may not want to add another hour of Internet browsing to that time. Even though you should definitely, definitely spend as much time as possible reading articles like these on the Internet.

[h/t: Science of Us]