A new study by the University of Vienna shows that particularly long periods of parental leave around the birth of a child are associated with a higher risk of unhealthy behaviour – specifically smoking – in the long term. The research team around Sonja Spitzer analysed the effects of maternity and parental leave on the smoking behaviour of mothers in 14 European countries: Austria, Belgium, Denmark, France, Germany, Greece, Ireland, Italy, Luxembourg, Portugal, Spain, Sweden, Switzerland, and The Netherlands. The study was recently published in the renowned Journal of Health Economics and is based on a collaboration with the Hertie School Berlin and the TU Vienna.

The length of career breaks taken around the birth of a child not only affects mothers' well-being and income, but also has a long-term impact on their health behaviour. In their new study, the researchers show that very long absences from work are associated with a higher risk of permanent smoking. At the same time, the results suggest that shorter periods of parental leave may have a protective effect. "We actually expected that longer career breaks would lead to mothers smoking less. However, our results clearly show that the likelihood of smoking later in life increases with longer periods of parental leave," explains study author Sonja Spitzer, a demographer at the University of Vienna.

"In principle, maternity and parental leave are important for health, and in the short term, health protection also outweighs other considerations. However, if the leave period is too long, financial burdens, social isolation and professional disadvantages can increase – smoking could be a coping mechanism for this stress. We were able to clearly show that longer leave periods increase the likelihood of smoking later in life. We can only speculate about the exact reasons behind this, but they are consistent with what we see in the literature and our data," says Spitzer.

Smoking is considered one of the biggest preventable health risks. "Our findings shed new light on parental leave policies: parental leave is intended to relieve parents, but it can also have unintended side effects on health – especially when there is financial uncertainty surrounding the birth," says Spitzer.

The research team linked large-scale survey data from over 8,500 mothers from the Europe-wide SHARE dataset with historical information on statutory parental leave regulations in 14 European countries between 1960 and 2010. Using an econometric method – the instrumental variable approach – the causal effect of the length of maternity leave on later smoking behaviour was investigated.

An additional month of maternity leave increases the likelihood of smoking later in life by 1.2 percentage points. For each additional month of maternity leave, the total duration of smoking (+7 months), the number of cigarettes consumed per day (+0.2 cigarettes per day) and the so-called 'pack years' (+0.6) also increase. Mothers who did not receive financial support from a partner around the time of birth are particularly affected. "Financial worries during an already sensitive phase of life such as around the time of birth can increase the pressure even more – this stress seems to have a particularly significant impact on health behaviour in the long term," says Spitzer. Shorter periods of parental leave, on the other hand, appear to have a potentially protective effect on smoking behaviour. The results suggest that the optimal duration of leave should be carefully considered.

The researchers have thus made an important contribution to the debate on the design of family policy measures: How long is too long? The results show that a careful balance must be struck between protection and care surrounding childbirth, financial aspects, labour market integration and long-term income for mothers, and societal goals such as gender equality – and, of course, the health of mothers.