You probably have some idea that you’re wasting time when you sit at your office desk through the dinner hour. Any boss worth his or her salt knows this, too. Now, there’s proof that even a formula-addicted economist could love. So as you sift through all the New Year’s resolutions you have already failed to keep this week, it’s not too late to preserve the most important one: Don’t work too much.
Really, you are wasting your time, and your employer’s time. Yet millions of Americans do just that. In a Gallup poll published last year, 4 in 10 Americans said they work more than 50 hours every week, and 2 out of 10 more than 60 hours. The average workweek is 47 hours!
A study published last year by John Pencavel of Stanford University makes the bold claim that productivity falls sharply after about 50 hours worked in a seven-day week. It falls off a cliff after 55 hours. In fact, folks who worked 70 hours in his study basically accomplished nothing more than folks who worked 55 hours. So, there it is. Go home for dinner.
There have been plenty of such studies before, but mostly using self-reported hours or inexact measures of output. Stuffy economists hate those. Pencavel used a neat data set he found that dated back to World War I at a munitions factory, when the need for output was infinite.
Right now, you are probably thinking that output at a munitions factory has nothing to do with output from your computer keyboard, and you might be right. But this is the trade-off that economists looking for hard conclusions with real data, rather than general assertions from anecdotes, must make.