The More the
Merrier? The Effect of Family Size and Birth Order on
Children's Education
Sandra E. Black, Paul J. Devereux (UCLA) and Kjell G.
Salvanes (IZA)
ABSTRACT
There is an extensive theoretical literature that postulates
a tradeoff between child quantity and quality within a
family. However, there is little causal evidence that speaks
to this theory. Using a rich dataset on the entire
population of Norway over an extended period of time, we
examine the effects of family size and birth order on the
educational attainment of children. While we find a negative
correlation between family size and children's education,
when we include indicators for birth order and/or use twin
births as an instrument, family size effects become
negligible. In addition, birth order has a significant and
large negative effect on children's education. We also study
adult earnings, employment, and teenage childbearing, and
find strong evidence for birth order effects with these
outcomes, particularly among women. These findings suggest
the need to revisit economic models of fertility and child
"production", focusing not only on differences across
families but differences within families as well.