Research carried out by researchers from four universities in Spain and Germany, involving UPF, the UB, UC3M and the University of Mannheim, studies the effect of women’s education on fertility and the health outcomes of new-borns at a time of improving gender equality in Spain. This is pioneering research in using a law on child labour to study these links in middle-income countries, engaged in a process of gender equality, as was the case in Spain a few years after the end of the dictatorship.

The researchers found that the reform led to an increase in the likelihood of having a first child prior to 37 weeks’ gestation and below-average birth weight.

To perform their analysis, the researchers used a reform implemented in Spain in 1980, which raised the legal minimum age for children to work from 14 to 16 years. Before the reform, when they reached the age of 14, children born at the start of the year had the possibility of leaving primary school and starting work. This possibility was not available to those born at the end of the year. This difference was abolished with the reform, which no longer foresaw the possibility of working at the age of 14 years, and it increased the incentives of those born in the first half of the year to remain in the education system. Thus, the research analyses the variation in the study cohort, comparing individuals born during the first and last months of the year, and prior to and following the labour reform.

Cristina Bellés-Obrero (University of Mannheim, Germany), Antonio Cabrales (Carlos III University of Madrid), Sergi Jiménez-Martín (Pompeu Fabra University), and Judit Vall-Castelló (University of Barcelona), the last two linked to the Centre for Research in Health and Economics (CRES-UPF), are the authors of the study, published in Working Papers by the Foundation of Applied Economic Studies (FEDEA).

In addition to noting that over the years the labour reform targeting minors led to an increase in the educational level of both men and women (an effect that had previously been examined), the study demonstrates that these legislative changes had an impact on the fertility of women and the health of new-borns.

According to the researchers, the labour reform led to an average of one month’s postponement of first births of the women analysed, although this delay was followed by a recovery effect and had zero impact on their completed fertility, i.e., making the assessment at the end of their period of fertility. Regarding the health of new-borns at time of birth, the researchers found that the reform led to an increase in the likelihood of having a first child prior to 37 weeks’ gestation (with a 0.23% increase) and below-average birth weight (4.15 grams less).

What is the study sample?

The researchers used administrative data of all births registered in Spain, which allows observing the universe of births occurring across more than 40 years (between 1975 and 2018). These data allow them to examine the completed fertility of women (and not just adolescent fertility, as in previous studies) as well as the health outcomes of infants at birth.

The researchers limit the sample to children of Spanish women born between 1961 and 1971 aged between 14 and 47 years at the time of delivery, and analyse data on women born in January, February, June, July, November and December. Thus, a total of 2,527,415 births and 1,393,937 first births were taken into account.

What caused the negative effects on the health of new-borns?

The researchers confirm two main reasons why the child labour law brought about this detrimental effect on the health of new-borns: first, the increased age of women getting pregnant for the first time, making their pregnancies riskier and increasing the chances of poor infant health outcomes.

Second, the changes caused by unhealthy habits: the reform increased the likelihood of women smoking and drinking alcohol. Additionally, they also find that the likelihood of quitting smoking during pregnancy is reduced for women born earlier in the year affected by the reform. “Delayed child-bearing and bad behaviours during pregnancy, such as smoking, are key to explaining the negative effect of the reform over infant health”, they assure.

“More educated mothers had smaller and more premature children due to delayed child-bearing and bad behaviours during pregnancy”.

But, they have also discovered that these negative effects on new-borns disappear in the medium term, when a reversal of the negative conditions takes place. On the one hand, more educated mothers contribute to a better health of their offspring making lifestyle choices for them (a better diet, for instance). On the other hand, they remain worried about the health of their new-borns as, for example, they have a significantly higher probability of having private insurance.

“More educated mothers, due to the reform, had smaller and more premature children due to delayed child-bearing and bad behaviours during pregnancy, however, they remained worried about the health of their children (as they assess their health status not to be good when their actual health is, indeed, good), the impact is insignificant in the medium term”, the researchers state.

In the opinion of the authors, their study fills a gap in research in this field for middle-income countries, as studies had been conducted in either highly developed or highly underdeveloped countries: “In Spain, this  gender equalization process then led to a convergence of health risk factors between men and women. Therefore, our results provide important policy implications for middle-income countries that are undergoing gender equalization processes right now”, they conclude.

Reference article:

Cristina Bellés-Obrero, Antonio Cabrales, Sergi Jiménez-Martín, Judit Vall-Castelló, 2021. “Women’s Education, Fertility and Children’ Health during a Gender Equalization Process: Evidence from a Child Labor Reform in Spain” Working Papers 2021-04, FEDEA.