Study: Longer working hours may be detrimental to health


Researchers investigate effect of increasing weekly working hours

If weekly working hours are increased by as little as one hour, this can have a negative impact on workers. Even a slight increase such as this is enough for workers to take a poorer view of their own health and go to the doctor considerably more often. These are the results of a study conducted by researchers from Martin-Luther-Universität Halle-Wittenberg (MLU) and Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), which was recently published in the journal Labour Economics.

The study led by Prof. Dr. Christoph Wunder from MLU and Dr. Kamila Cygan-Rehm from the Chair of Empirical Economics at FAU is one of the first to investigate the correlation between increasing weekly working hours and the consequences this has for health. In descriptive analyses, there often appears to be a positive connection between health and working hours, for example when healthier people work longer. Until now, however, only little has been known about the causal effects of increasing working hours on people’s health. ‘From an empirical point of view, proving the influence of longer working hours on health is very difficult, as you have to exclude unobserved factors, such as personal motivation, which can lead both to longer working hours and to improved health, distorting the direct causal effect,’ explains Dr. Cygan-Rehm.

More than 12,000 private households surveyed

In order to shed light on this correlation, the two researchers evaluated data collected by the German Socio-Economic Panel (SOEP) between the years 1985 and 2014. This is the largest and longest-running project of its kind, within the context of which more than 12,000 private households have been interviewed with respect to their circumstances over a period of more than 30 years. The SOEP data give information, for example, on education, health, income, employment and life satisfaction. As the same people are surveyed each year, the SOEP data can also be used to give an indication of long-term trends and reactions to external changes such as working hours.

Both scientists discovered that increasing working hours by as little as one hour had significant consequences. When asked to assess their own health, those surveyed gave an assessment which was two percent lower than before and the number of visits to the doctor increased by 13 percent. Those most affected by these negative effects were women and families with young children. ‘We suspect that the effects are more pronounced in these groups, as they are faced with considerable constraints on their time outside of working hours. If working hours increase, this has a knock-on effect on time pressure outside of work,’ according to Prof. Dr. Christoph Wunder from MLU.

Small change, considerable effect

The study only covers data from employees from the former West Germany, who were employed in the public service or as public servants. ‘Changes to the regulations governing working hours tend to affect employees in the public service more than employees in the private sector, who tend to keep their weekly working hours consistent by altering the amount of overtime they do if there are any changes to regulations stipulating working hours. Staff working in the public service are less flexible,’ explains Wunder. Between 1985 and 1991, weekly working hours initially fell from 40 to 38.5 hours. Later, working hours for public servants in Bavaria and Hessen increased up to a maximum of 42 hours per week. These fluctuations did not occur in the Eastern states of Germany, in the former DDR. The study does not give any indication of the optimum working hours. It does, however, give an insight into what consequences even just a slight change can have.

Study: Cygan-Rehm K. & Wunder C. Do working hours affect health? Evidence from statutory workweek regulations in Germany. Labour Economics (2018). doi: 10.1016/j.labeco.2018.05.003

Further information:

Dr. Kamila Cygan-Rehm

Addition information