Research
Working papers
When Young Boys Can't Wait: Academic Redshirting and Relative Age Effects on ADHD Referral, Diagnosis, and Treatment (Solo-authored) Manuscript
Abstract: I study how changes in parental discretion over school starting age (academic redshirting) affect gaps in ADHD referral, diagnosis, and treatment between young- and old-for-grade children. I exploit a tightening of redshirting rules in Denmark combined with quasi-experimental variation in school starting age from the school entry cutoff. Using a fuzzy regression discontinuity design, I find that gaps in ADHD referral, diagnosis, and treatment increased from negligible up to 1 percentage point (18% of the mean) for boys after the policy change. For girls, who were less likely to be redshirted and therefore less exposed to the tightening, substantial but imprecise gaps were present before the policy change and did not change after. This suggests that academic redshirting mitigates disparities in ADHD outcomes and points to possible overdiagnosis of young-for-grade children, underdiagnosis of old-for-grade children, or both when redshirting is less available.Work in progress
Age-at-Test and the Gender Achievement Gap (with Helena Skyt Nielsen)
Abstract: When reaching high-stakes exams at the end of lower secondary school, boys are on average 1.5 months older than girls, because they are more often redshirted or grade retained. Using variation in age at test across birth months, we show that this gap explains 20 percent of the gender gap in mathematics and 3 percent of the gap in Danish. Although boys retain an advantage in some socio-emotional outcomes after controlling for age at test, effects carry over to long-term outcomes such as enrolment into secondary education. Our findings suggest that strict enforcement of school-entry legislation contributes to a school system that favors girls.
Relative age and mental health (solo-authored)