Family Composition and Children’s Educational Outcomes

This paper explores the relationship between sibship structure and educational outcomes, in the context of theories of dilution of parental time. Special efforts are made to disentangle the effects of family size and birth order, since these effects have often been confounded in the past. Children from larger families are found to do worse than children from smaller families, and children lower down the birth order do worse than those higher up the birth order. These findings are consistent with theoretical predictions, but the finding that only children perform worse than those from two-child families, even controlling for a whole range of parental and school characteristics, is not. This paper suggests that as well as inputs from parents, interactions with other children may be important in children's educational development: this idea is supported by the finding that mixing with other children outside school reduces the disadvantage otherwise associated with being an only child. Additionally, the important finding emerges that only children are at much more of a disadvantage on mathematically-based measures of performance than on language-based measures, suggesting that these skills may be acquired via different processes.