Last week I filled in a form that asked me how many hours I worked every week. I stared at it blankly. It’s a pretty basic question, and I ought to be able to provide an answer straight off.

Yet because my work sprawls across my life and because I am not sure what counts as “work” any more, I really don’t have a clue. All I can say is that I do quite a lot of it. But as “quite a lot” wasn’t an option, in the end I wrote down 45.

Later on, I put the same question to a group of acquaintances including a lawyer and a company director. All hummed and hawed for a bit but then said they worked more than 40. The writer said 42, the director 70 and the lawyer 65.

I now find we were all of us talking through our hats. None of us works anything like as hard as we think we do. According to studies in the US and elsewhere, people routinely overestimate their working hours by at least 10 per cent – when you compare how hard people say they work to diary entries, the two don’t tally.

In itself that isn’t terribly surprising. We are all famously useless at estimating how long we spend doing anything. Time-use studies show we wildly overestimate the amount of housework and underestimate sleep – ask an insomniac how much she slept last night, and she’ll say two hours, when it was actually closer to five.



Bumping up

What is unusual about the work estimates is that the longer people actually work the more they overestimate it. Those who work 37 hours estimate that they work 40. But people who work 50 hours bump up the estimate by a whacking 25 hours and claim to work 75.

The reason for this, I first thought, must be because the longer you work, the more painful each marginal hour feels. When you have already done 50 hours, the 51st feels very long indeed. Yet this doesn’t tally with the fact that the people who overestimate their work most are the people who have most reason to enjoy it.

Jonathan Gershuny from Oxford university and John Robinson of University of Maryland have done a study that breaks down the overestimation by profession.

They found that lawyers overestimate more than paralegals; doctors overestimate their hours more than nurses. Chief executives overestimate their hours far more than lowly part-time workers, who are more likely to underestimate.



Status

Prof Gershuny thinks there are two reasons for this. The first is to do with status. The lower you are in the pecking order the lower the value you put on your own contribution. If you are CEO, you rate your own work so highly that the quantity of it becomes distorted in your own mind.

But it is also because work is a badge of honour. A man’s worth was once measured by how much leisure he had, and then by how much money. Now that it is harder to pass money down to children, your heritage is measured through your “human capital”. And the best measure of that is how hard you work.

You could say it doesn’t matter much if we tell ourselves we work longer than we do. Assuming the lawyer doesn’t bill us on the estimated hours, it should be good news that we are not as wildly overworked as we think we are.



Frazzled

But if the disease of overwork is at least partly in our minds, it still does matter because it has a bearing on how stressed we feel. If I believe I do a 60-hour-week, I’m going to feel more frazzled than if I think I do a 40-hour one.

Worse, the long-hours delusions of macho workers have a bad effect on the rest of us. The more they claim to work around the clock, the more inadequate everyone else feels.

To get a better idea of my own hours, last week I resolved to keep a diary – only to give up almost at once. Lying in the bath I was thinking through the arguments for this column. Was that a bath, or was it work? And what about when I was in the office vaguely emailing and vaguely doing the grocery shopping online?

So I have scrapped the diary and have simply decided to revise down the number of hours I tell myself I work. It is not 45. The quantity of real, proper work, is probably barely half that. But I am telling myself this is fine. Hours, after all, may be the only measure we have of work, but they are a pretty feeble one.

One of the finest writers I know never gives any outward sign of doing any work at all. I emailed him just now to ask how many hours a week he puts in. His answer didn’t make me feel great either – though for rather different reasons. “Five – max.” – (Copyright The Financial Times Limited 2014)