Media Briefings


  • Published Date: October 2016

Children who start school at a younger age are more likely to commit crimes before they reach their early twenties. Parents who enrol their offspring in school at a later age may benefit from a permanent reduction in the number of crimes committed by boys. For girls though, a higher school starting age simply postpones the initiation of crime.

These are among the findings of research by Rasmus Landersø, Helena Skyt Nielsen and Marianne Simonsen, which is forthcoming in the Economic Journal. Their study analyses data on almost 100,000 children in Denmark, who have been followed from childhood into adulthood. The researchers link information on the age at which a child starts school (first grade) to subsequent crime from population-level, administratively collected data.

They note that one of the most prevalent findings in criminology is the crime-age profile; that crime rates peak around age 18-20 and then decrease for the remainder of people’s lives. But while age is an important determinant of crime, the new study finds that early life decisions made by parents on behalf of children – such as when to enrol them in school – also affect this relationship between crime and age.

Some children are more likely to start school late than others. This means that a simple comparison of children who start late and early in school will not represent the actual effects of school starting age, but only outcomes associated with school-readiness.

To obviate this, the authors make use of the fact that according to administrative guidelines, Danish children are supposed to start first grade during the calendar year in which they turn seven. Children born in late December are, therefore, much more likely to start school at a lower age than children who are, by mere chance, born just a few days later in early January.

Thus, a comparison of crime outcomes for children born just before New Year with children born just after will isolate the effects of age at school start on subsequent crime.

Exactly how is the age at which children start school related to the crime-age profile? The missing link is the mechanical connection between school starting age and children’s later lives. Starting school one year later also postpones key events later in life by one year – for example, enrolment in post-secondary education and graduation.

Thus, the effects of school starting age on crime inform the broader question about the crime-age profile. Is the crime-age profile merely shifted along with school starting age, suggesting that the timing of key life events is the driving mechanism? Or is the crime-age profile affected in other ways, suggesting that age and maturity in themselves are important?

The researchers find that a later school start lowers the propensity to commit crime before teenagers reach their early twenties. Girls who start school one year later are two percentage points less likely to have committed any crime before the age of 19; boys are five percentage points less likely.

But the effects fade later in life. Hence, the propensity to commit crime is affected by the timing of key events throughout the teenage years.

Yet the results also point to a permanent reduction in the number of crimes committed for boys, while for girls, a higher school starting age simply postpones the initiation of crime. This suggests that age and, for example, maturity also constitute important mechanisms underlying the crime-age profile for boys but not as much for girls.

The study provides new insights into the observed relationship between age and criminal behaviour. It also illustrates the fact that parents’ decisions about their children’s early lives – such as when to enrol them in school – not only affect their academic and labour market performance in later life, but also other behavioural characteristics. This may have important consequences for the individuals themselves and for society as a whole.


Notes for editors: ‘School Starting Age and the Crime-Age Profile’ by Rasmus Landersø, Helena Skyt Nielsen and Marianne Simonsen is forthcoming in the Economic Journal.

Rasmus Landersø is at the Rockwool Foundation Research Unit. Helena Skyt Nielsen and Marianne Simonsen are at the Department of Economics and Business Economics at Aarhus University.

For further information: contact Romesh Vaitilingam on +44-7768-661095 (email:; Twitter: @econromesh); Rasmus Landersø via email:; Helena Skyt Nielsen via email:; or Marianne Simonsen via email: