Is the association between education and fertility postponement causal? The role of family background factors

A large body of literature shows a positive relationship between education and age at first birth. However, this relationship may in part be spurious due to family background factors that cannot be controlled for in most research designs. We investigate to what extent education is causally related t...

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Bibliographic Details
Main Author: Tropf, F
Format: Journal article
Published: Springer 2017
Description
Summary:A large body of literature shows a positive relationship between education and age at first birth. However, this relationship may in part be spurious due to family background factors that cannot be controlled for in most research designs. We investigate to what extent education is causally related to later age at first birth in a large sample of female twins from the UK (N=2,752). We present novel estimates using within-identical twin and biometric models. Our findings show that one year of additional schooling is associated with about half a year later age at first birth in OLS models. This reduced to only 1.5 months for the within-identical twin model that controls for all shared family background factors (genetic and family environmental). Biometric analyses reveal that it is mainly influences of the family environment – not genetic factors – that cause spurious associations between education and age at first birth. Lastly, we demonstrate using data from the Office for National Statistics that only 1.9 months of the 2.4 years of fertility postponement for birth cohorts 1944-1969 could be attributed to educational expansion based on these estimates. We conclude that (the rise in) educational attainment alone cannot explain differences in fertility timing (between cohorts).