Imitation, Contagion, or Exertion? Using a Tax Reform to Reveal How Colleagues' Sick Leaves Influence Worker Behaviour

We analyse the social interaction effects in sick‐leave behaviour in the workplace, using high‐quality Norwegian matched employer–employee data with detailed individual information on sick leaves during the 2004–2006 period. We find that social interaction effects in sick‐leave behaviour in the workplace do exist, and that the effects are noticeable in size. The strong relationship between the sick‐leave rates among colleagues is not solely the result of contagious diseases, nor is it caused by improved informational quality or by the increased workload for the non‐absent workers. Evidence supports the existence of reciprocal worker behaviour that is unrelated to joint leisure‐seeking activities.