The more female classmates at school, the higher a woman’s pay later on

Men and women should earn the same amount of money. But they do not; women tend to have different professions than men and also earn less. The prevailing opinion is that this “gender gap” needs to be closed. But to this day, it is still not entirely clear where it originates. A study based on Swedish data addresses this issue. The results suggest that the gender environment has a major influence on career development and salary from an early age.

According to the study, girls benefit if the composition of their classes is in their favor during their mandatory schooling – that is, between the ages of 6 and 16. The study reveals that the more girls in a class, the higher a woman’s later salary and the smaller the gender wage gap (the difference in pay between men and women).

This is shown in the data analysis carried out by Professor Armando Meier of the University of Basel and his co-author Professor Demid Getik of the University of Durham. For their study, the pair analyzed data from more than 750,000 pupils who had completed their primary education in Sweden between 1989 and 2002. The researchers have published their findings in the American Economic Journal: Economic Policy.

Wage gap reduced by 2.7%

According to the study, girls in female-dominated classes have better grades and are more likely to pursue career pathways that are considered “typically male”. For example, they are more likely to choose a scientific or technical focal area in high school and later work in male-dominated professions.

At the age of 30, women who were in a class consisting of 55% girls earn about $350 more annually than women whose class had a 45% proportion of girls. This means a 2.7% reduction in the gender wage gap. However, working in sectors where wages are generally higher is not the only reason that the women earn more. They also earn more within a specific industry than women from another school environment.

The fact that school environment influences grades and further education is not a new finding. “Until now, however, it was unclear to what extent the gender ratio in a school class affects long-term career choice and salary,” says Armando Meier, professor of economics. “Our analysis shows that gender ratio has a causal influence on later education and career paths as well as on income.” The results cannot be explained by factors such as family environment, socioeconomics or own gender: the proportion of girls in the classes is the only feature that stands out.

Data for the whole population

Sweden is particularly well suited for analysis because, for one thing, data is available for the entire population over a long period of time. For another, primary education lasts from 6 to 16 years of age. This means that the same conditions apply to all children and young people for a relatively long time, explains Meier. There is no specialization until after mandatory schooling has been completed. Furthermore, the composition of classes is almost random, sometimes with more girls and other times, more boys.

“Women benefit most from this effect if the proportion of girls in their class was 55% or more,” says Meier. We can only guess what the reasons are. It is possible that there is less violence and a different kind of rivalry in girl-dominated classes. “Psychological literature exists on these aspects, but it is not possible to make more detailed statements about them using our data,” says Meier. 

Network effects could also play a role, as the economist speculates: girls from female-dominated classes often attended the same secondary schools and universities and thus profited from long-term contacts that could benefit them in their working lives.

However, “as soon as the girls benefit, the boys experience a disadvantage,” says Meier. Starting at a proportion of girls of 55%, a negative effect can be observed for boys in terms of later income.

The benefit for society as a whole

So should we return to single-sex classes in order to improve equal opportunities in the labor market? Meier believes: “For policy-makers prioritizing career prospects, that could be one possible conclusion. But school is also about promoting social skills.” However, it might be worth considering teaching some subjects in single-sex classes, as is sometimes the case with sports education in Switzerland. Psychological studies show, for example, that girls in a female-dominated environment rate their mathematical abilities better and get better grades.

The findings of the study make it clear how important it is to set the course for an equal working environment in the educational system – a win-win situation for society as a whole.

Original publication

Demid Getik and Armando N. Meier
The Long-run Effects of Peer Gender on Occupational Sorting and the Wage Gap
American Economic Journal: Economic Policy (2024), doi: 10.1257/pol.20230251