The Effect of Childhood Family Size on Fertility in Adulthood: New Evidence From IV Estimation

Abstract

Although fertility is positively correlated across generations, the causal effect of children's experience with larger sibships on their own fertility in adulthood is poorly understood. With the sex composition of the two firstborn children as an instrumental variable, we estimate the effect of sibship size on adult fertility using high-quality data from Norwegian administrative registers. Our study sample is all firstborns or second-borns during the 1960s in Norwegian families with at least two children (approximately 110,000 men and 104,000 women). An additional sibling has a positive effect on male fertility, mainly causing them to have three children themselves, but has a negative effect on female fertility at the same margin. Investigation into mediators reveals that mothers of girls shift relatively less time from market to family work when an additional child is born. We speculate that this scarcity in parents' time makes girls aware of the strains of life in large families, leading them to limit their own number of children in adulthood.

The causal effect of an additional sibling on completed fertility: An estimation of intergenerational fertility correlations by looking at siblings of twins

“…This is different from another common IV used to estimate exogenous changes sibling size -sex composition of previous siblings. Analyses using this approach show positive effects of an additional sibling for sons, and negative effects for daughters (Cools and Hart 2014). These results might differ from the results of the approach used here, due to differences between planned and unplanned children (such as parental satisfaction with their family size).…”

“…Different parity progression ratios based on sex composition of children are found in developed countries (e.g., Andersson et al 2006;Kolk and Schnettler 2013). This approach is used in ongoing work examining intergenerational transmission of fertility (Cools and Hart 2014). This approach, unlike a twin IV, estimates the effect of an additional planned (and wanted) birth instead of an unplanned additional sibling, which may differ in how it affects the experience of an additional sibling (e.g., the general satisfaction of the parents may differ).…”

The Effect of Sibling's Gender on Earnings, Education and Family Formation

“…Several studies show that the gender of current children influences parity progression, that is, the probability of having additional children (see Angrist and Evans, 1998;Black et al, 2005;Conley and Glauber, 2006;Åslund and Grönqvist, 2007;Dahl and Moretti, 2008;Cools and Kaldager Hart, 2015). In developed countries, the most common finding is that parents of two boys or two girls are more likely to have additional children than parents of a boy and a girl.…”

“…In this spirit it is worthwhile to discuss a recent paper by Cools and Kaldager Hart (2015) on fertility outcomes. Using a sample of Norwegian singletons, they examine how sibling sex composition affects fertility.…”

Grandparental availability for child care and maternal labor force participation: pension reform evidence from Italy

“…The coefficient on the inverse Mill's ratio is positive, but conditioning on a large set of 25 The estimates in this section must be nonetheless interpreted with caution because some residual endogeneity may remain if the spouse's only-child status is affected by unobservable variables that also determine her partner's LFP. To the best of our knowledge, the existing literature focuses mainly on motherson or mother-daughter intergenerational fertility correlations (e.g., Kolk 2014; Cools and Kaldager Hart 2016), while much less is known about the relation between a woman's fertility choices and her partner's family size. controls is not statistically significant at conventional levels.…”