The role of working conditions in sickness absence

Economists have paid very little attention to the role of working conditions in sickness absence. Yet, bad working conditions are a potential determinant of labour supply, either directly or through their impact on health. This study tries to shed some light on this issue. To begin with, we examine a model of labour supply which explicitly takes into account the employees health status and its evolution. This model provides a useful framework in order to interpret and disentangle the links between working conditions, health status and work. In particular it shows that two effects occur: bad working conditions have a negative impact on health and labour supply. But this can be compensated by a wage effect, if bad working conditions are compensated by higher wages. Thus the impact of working conditions on absenteeism is theoretically ambiguous. This requires an empirical estimation in order to determine which effect prevails. We specifically study the impact of working irregular schedules on absenteeism for male manual workers in private sector. We use a propensity score matching method. In order to check the robustness of our estimates we also use a selection on unobservables specification. Our estimates show that working irregular schedules has a significant impact on sickness absence: roughly 20 % of the employees with irregular schedules who were absent for sickness reason would not have stopped working if their schedules were regular. This effect is definitely more important than that estimated by simple descriptive statistics. Nevertheless, the sign and the extend of the effect depend on age.