Explaining Cross-National Variation in the Effect of Sibship Size on Educational Achievement

Hyunjoon Park, University of Wisconsin at Madison

Although an inverse relationship between the number of siblings and educational outcomes has been one of the most consistent patterns found in social science literature, evidence also suggests substantial variation across countries in the magnitude of the sibship-size effect. Using data from PISA, I examine the relationship between sibship size and educational achievement among 15-year-olds across 40 countries. Two-level hierarchical linear models (HLM) are used to assess the extent to which the effect of additional siblings on educational achievement varies across countries. I explore sources of the cross-national variation by modeling within-country slopes of sibship size as a function of country-level characteristics. I particularly focus on the roles that prevalence of extended family, the degree of governmental support for families, and country’s economic level play in shaping the effect of sibship size. This study extends recent discussion on the significance of institutional contexts for influencing educational stratification.