Birth order, sibling size and educational attainment in twentieth century Spain

ABSTRACT This research presents new evidence on the negative associations of the number of siblings and birth order with years of schooling among female and male Spanish cohorts born in the first six decades of the twentieth century. Special attention is given to unravelling the separate effects of both factors, sib size and birth order. Based on data from the 1991 Spanish Sociodemographic Survey (SDS), findings in Spain support the theoretical framework of the family conditional resource dilution model and indicate that both number of siblings and birth order have been important and relatively independent factors in reducing educational attainment. The association of family size and birth order with educational attainment was contingent to a significant extent on socio-economic status. Whereas the educational consequences of number of siblings are not uniformly distributed by social class, the results for birth order are much more homogeneous. This suggests that parents in high socioeconomic statuses were able to limit the effects of dilution induced by the number of siblings while the dynamics of the dilution of resources associated with the birth order depended, in part, on factors not entirely controllable by families.