Is there a cost associated with an increase in family size beyond child investment? Evidence from developing countries

Using multiple births as an Instrumental Variable (IV) for family size and data for 43 developing countries, I find evidence that a shock in fertility has a cost for a family as a whole. Mothers are more likely to live under less stable family arrangements and they are more likely to use contraceptives. Children are less likely to receive some vaccines, attend school, live their mother and there is an increase in odds of mortality. The analysis by level of development reveals the cost of fertility comes from those countries with lower level of development.