Multiplying Siblings: Exploring the Trade-off Between Family Size and Child Education in Rural Bangladesh

The question of whether large families have a subsequent negative impact on child health, education, and welfare is of pressing concern for development and public health policy. We tackle this question by empirically exploring whether parents face a trade-off between increasing the size of their family and investing in their children. Using data from a rural sub-district in Bangladesh (the 1996 Matlab Health and Socioeconomic Survey), we estimate the effect of siblings on school attendance, literacy, and numeracy. We use an instrumental variables approach, instrumenting first for children’s sibship size their mothers’ menarche age, and also instrumenting for children’s sibship size with the household’s treatment status (in the Matlab family planning experiment). Although we find no effect of siblings on school attendance, we find that additional siblings increase the likelihood that children are literate and numerate. These effects are greater for girls and younger siblings, consistent with positive numeracy and literacy spillovers from older siblings to younger ones. The results provide counter-evidence to the quality-quantity trade-off theory and demonstrate that sibling education spillovers may dominate any reduced investment on the part of parents.