School Starting Age, Fertility, and Family Formation: Evidence From the School Entry Cutoff Using Exact Date of Birth.

In the past 50 years, the age at first birth in Norway and other European countries has shifted, leading to concerns that individuals begin childbearing too late to reach their intended family size. This article analyzes the effect of school starting age on fertility and family formation by utilizing Norway's age-based school entry policy. Using individual-level register data and a regression discontinuity design, we find that being born after the age cutoff for school start results in an increased age at first birth of 2.9 months for women and 4.0 months for men, whereas completed cohort fertility was unchanged. Similarly, being born after the cutoff increased the age at first marriage by 4.7 months for women and 2.4 months for men, with no effect on the overall probability of having a partner. Results show that age at completed education and earnings development are important mechanisms in this fertility postponement. Additionally, we analyze detailed age- and parity-specific effects, providing important insights into how age at starting school affects fertility timing but not overall fertility.