Girls who start school early live a wild life as teenagers

Assistant professor of economics Eva Rye Johansen has received the Aarhus University Research Foundation PhD talent prize of DKK 50,000 for her extraordinary research results and research communication about teenagers' risky health behaviours.

Eva Rye Johansen
Assistant professor Eva Rye Johansen Photo: Anne Kring

Can data from national health registers be used to identify inadequately discussed causes and consequences of teenagers’ risky health behaviours? Yes, if, as Economist Eva Rye Johansen, you specialise in applied microeconometrics, that is, finding statistical methods for processing data about the behaviour of individuals.

“I have used statistics of Danish women born between November 1981 and February 1992. In addition to information about school start, I have looked at data for alcohol poisonings, abortions, births and treatment for chlamydia. The data show that the age of the girls when they start school has an influence on their risky health behaviour when they reach their teens,” Eva Rye Johansen summarises.

She is one of five PhD graduates at Aarhus University to receive the Aarhus University Research Foundation PhD talent prize of DKK 50,000 for her extraordinary research results and research communication.  

In her PhD project, she has compared large groups of girls of nearly the same age, who were born shortly before and shortly after the turn of a year, and who have therefore started at different grades. Her studies show that girls who start school early, also start drinking and having sex at a relatively younger age.

However, Eva Rye Johansen’s analyses also reveal that the group of girls starting school early have a slightly higher risk of having an induced abortion when they are 15-20 years old, in fact 36% higher than the average. And they also have an increased risk of getting alcohol poisoning, which happens 58% more frequently than the average.

Research and politics

This is not the time or place to describe immediate results and methodical design. However, Eva Rye Johansen’s results are a good example of how the rather unique Danish register data can be used in a way that resonates with the research community – her sole authored article has been published in the leading international Journal of Health Economics.

At the same time, her findings show how microeconometrics can contribute valuable knowledge in the preparation of efforts or policies in relation to social issues.

“For example, you may have a political objective that 15-year-olds should drink less or that fewer 18-year-olds should become pregnant. However, perhaps focus should instead be on the grade they are in,” Eva Rye Johansen suggests.

Focus on family economy

The two other chapters in her PhD thesis have been co-authored with two other researchers, and they look into the consequences of teenage pregnancies.

“First we show that becoming a teen parent has negative consequences for both the mother and the father. It may also be useful if a policy in the area would not only support the young mothers but also the fathers. The last chapter focuses on the consequences for the children. It seems that the young age of the parents is not the only reason why the children do not do well but that a number of other factors are also involved,” says Eva Rye Johansen.

She now continues her research as an assistant professor at Aarhus University where she uses microeconometrics to study causes of social inequality.