Some people may experience flexible guilt, and feel they have a responsibility to put in more hours, because workers being able to choose their own hours is seen by some employers as a privilege.

“They feel obliged to justify the legitimacy of working from home or in their own time, by showing they are equally or more productive,” Moen says.

Chung explains it a different way: “In general, if you have more control over your working hours you tend to worry more when you are not at work – and this is especially the case for those workers with most control over when and where they work. This increase in tendency to worry seems to be highest in countries with high unemployment rates, less stable labour market conditions and if employees have a lack of negotiating power.”