Interesting the types of information that comes up when one googles.
Study: People Claiming to Work More Than 70 Hours a Week Are Totally Lying, Probably
Take part of this for what it's worth since it's from the US Bureau of Labor Statistics:
Bureau of Labor Statistics (PDF) in a study highlighted by Harvard Business Review. When asked how much work they do each week, Americans tend to report longer hours than when they keep a more accurate diary of their work, the BLS analysis found. For instance, a person who actually works 40 hours in a week will, on average, report working 43.
Not only that, but the more hours that people work, the more they exaggerate. Americans who say they work 75 hours a week tend to be exaggerating by 25 hours. (The average American work week in September was 34.5 hours, according to the BLS.)
It's hard to say whether people are just bad at estimating their work weeks, are intentionally inflating their hours, or some combination of the two. The BLS suggests that at least one factor is the "social desirability" of work. People may overstate their working hours out of fear of being considered lazy, especially if they are part of a social class that puts a premium on people who work too much.
"“Perhaps one of the most important accomplishments of my administration has been minding my own business.”" — Calvin Coolidge