The appropriate length of maternity leave and parental leave remains a frequently debated sociopolitical issue. A research group from Vienna has now added a new piece to the discussion in the Journal of Health Economics. Their large-scale study, based on data from several decades across 14 countries — including Austria — reveals a surprising link: the longer the parental leave, the more likely mothers are to take up smoking afterward.
What counts as “too short” or “too long” in terms of parental leave is highly controversial in political debate and difficult to pin down scientifically. Together with health economists, lead researcher Sonja Spitzer from the University of Vienna analyzed survey data from over 8,500 mothers collected in Europe-wide health surveys and combined it with statistics on relevant legislation in 14 European countries between 1960 and 2010.
Austrian data on “unintended consequences”
The researchers looked for “quasi-experiments” — system changes such as reforms in parental leave policies — which can be interpreted as “shocks” whose effects can be statistically estimated. In 2023, Caroline Chuard from the University of St. Gallen (Switzerland) had already shown that longer parental leave — i.e., longer absence from the labor market — can have negative health effects. Her research, based on Austrian policy changes in the 1990s, found that extending leave from 1.5 to 2.5 years was associated with slightly worse mental health outcomes later on.
Researchers refer to these as “unintended consequences” of the time off that is undoubtedly necessary for mother and child. In German-speaking countries, parental leave is traditionally long by international standards, Spitzer told APA: Austria, with an average duration of 27 months, is among the leaders, while in the U.S., parental leave is often minimal or non-existent.
When smoking was marketed as relaxation
The researchers initially assumed that longer parental leave would benefit mothers’ health — for example, because they spend more time near their baby and would thus avoid smoking. However, only a few decades ago, tobacco companies ran ads targeting mothers, promoting smoking as a way to relax from parenting. Indeed, the data points — at least from today’s perspective — in an unexpected direction.
On average, across countries and over time, the likelihood of later smoking increases by 1.2 percentage points with each additional month of leave. The number of cigarettes smoked daily rises by 0.2, and the total duration of smoking increases by up to seven months. These relatively large differences were found in comparison groups directly affected by changes in leave policies, according to Spitzer.
Lack of partner support increases effect
The researchers controlled for various other possible influencing factors, but the link between longer leave and higher smoking rates remained. “We’re quite confident these are causal effects,” said Spitzer. “We believe we’re observing a stress mechanism.”
The effect is stronger among women who did not receive financial support from their partners around the time of childbirth. “We conclude that financial stress plays a role. Smoking is often a way to cope — a coping mechanism.”
No “ideal leave duration” and still low male participation
There is no “ideal parental leave duration” that can be scientifically applied across all groups and countries, Spitzer emphasized. Increasing already long leave periods in Austria or Germany likely makes little sense, while in countries like the U.S., even a few extra weeks could have positive health effects.
The team — which also included researchers from TU Vienna and the Hertie School in Berlin — originally aimed to study the effects of parental leave among men. However, participation levels were so low that no meaningful calculations could be made — a finding that should give pause, Spitzer noted.
