Sibling size and investment in children's education

"This study consistently estimates the trade-off between child quantity and quality by exploiting exogenous variation in fertility due to son preferences. Under son preferences, childbearing and fertility timing are determined conditional on the first child's gender. For the sample of South Korean households I find strong evidence of unobserved heterogeneity across households. However, sibling size has adverse effects on per-child investment in education, in particular when fertility is high"--Forschungsinstitut zur Zukunft der Arbeit web site.