Here's why it's pointless to work more than 50 hours a week

How many hours do you work a week? If the answer is more than 50, research suggest it is too many.

A study from Stanford economist John Pencavel, highlighted in a recent post on Quartz, found that people who work 70 hours or more per week tend to get the same amount done as those who work 55. Increases in productivity after 50 hours of work in a week were "minimal".

To establish this, Pencavel looked at research into munition workers carried out by the Health of Munition Workers Committee (HMWC) during the First World War when people were working up to 90 hours, seven days a week, making weapons.

The HMWC recommended men should work no more than 67 hours a week and women 60. They were also critical of Sunday work, as their findings showed "seven days’ labour only produces six days’ output".

Pencavel re-examined the HMWC data and concluded "long weekly hours and long daily hours do not necessarily yield high output". He also found that denying workers a day off reduced output by around 10 per cent.

The reason why? Stress and fatigue reduce employee productivity after 55 hours and actually "increases the probability of errors, accidents, and sickness that impose costs on the employer".

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