Understanding the Effects of Sibling Composition on Child

This paper argues that spacing between consecutive births is an important aspect of competition among siblings for survival. Since parents simultaneously choose their desired values of birth spacing and the amount of time and other resources invested in children (which in turn affect child mortality), we use a maximum likelihood method to model birth spacing and child mortality as correlated processes while also allowing for family specific unobserved heterogeneity. Our estimates show that the chances of survival in the eastern Indian state of West Bengal increase with an increase in birth interval (prior and/or posterior) and decrease with the birth of a twin.