Age at school entry: How old is old enough?

A child’s age at school entry matters, and the implications of policy changes can have long-lasting effects

University of Toronto, Canada, and IZA, Germany

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Elevator pitch

Laws on age at school entry affect student achievement and often change for a number of reasons. Older students are more mature and ready to learn. This can have positive impacts on academic, employment, and earnings outcomes. The costs of holding children back include another year of childcare expenses or income forgone by the caregiver parent. Entering the workforce one year later also has implications for lifetime earnings and remittances to governments. School-entry policies could be a useful tool in increasing student achievement, but the short- and long-term impacts need to be better understood.

Oldest students have an advantage over
                        youngest students in mathematics

Key findings


The school-entry age has been decreasing around the world; however, in the US, the opposite has been occurring.

The trend in the US is partly due to changes in school-entry cut-off dates, but more parents—often of higher incomes—are also delaying their children’s school entry.

Increasing the school-entry age by changing the cut-off date can lead to increased future wages.

Being the oldest student within a group has strong short-term effects on outcomes, such as test scores, special-needs diagnosis, and leadership.


The optimal school-entry age is unknown and likely to depend on external factors, such as access to early childhood education.

More parents in the US are delaying their children’s school entry, despite mixed evidence of its benefits.

Findings on the effects of being older within a student group are inconclusive with respect to long-term outcomes, such as educational attainment, employment, and earnings.

It is uncertain whether the positive effects of being older within a group are due to the student’s age relative to their peers or the student’s absolute older (calendar) age.

Author's main message

The school-entry age has been decreasing globally, but the opposite is occurring in the US. School-entry cut-off dates continue to change; parents are also holding their children back to increase their learning readiness. There are advantages in being older at school entry, but younger students also benefit from having older students in the same class. However, the optimal school-entry age is still unknown and likely depends on jurisdictional factors such as access to early childhood education. As changes in school-entry age affect student achievement, policymakers need to decide what the optimal age is and the best way to implement it.

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