Employee absenteeism is a problem for companies everywhere. When employees are away from the office, for good reasons or not, the cost has been measured at somewhere around 4 percent of the world’s gross domestic product. Absences lead to delayed work, colleagues take on more, and projects are hampered, thus reducing productivity for the firm as a whole.

This is one reason firms are investing heavily in health interventions, from fitness regimes to cafeterias serving up fresh produce. This may help boost employees’ immune systems, but it might not always curb absenteeism. While employees take an average of seven to 10 workdays a year for medical reasons, many also take “slack days” on top of these legitimate days off. These can be days off due to stress, boredom, tiredness, or simply prolonging their sick leave unnecessarily, milking their absence for an extra day. Some firms are affected more than others, with some losing more workdays due to absenteeism than others. Others face the opposite problem: Employees who love their jobs so much they show up for work even when they’re sick. Why this is the case has not been extensively explored.

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