Abstract
This paper investigates the association between changes in coresident sibship size and children's educational progress in the Philippines. When conceptualized at the household level, sibship size is a dynamic aspect of the family context with potentially important implications for resources needed to support a child's education. Individual-level change models suggested that adding younger siblings in early childhood (from birth to age 9) and losing both younger and older siblings later in childhood (from age 9 to 19) were associated with less educational progress by the focal child between ages 9 and 19. These effects were additive and indicated the importance of assessing both type of change and timing in evaluating the relationship between coresident sibship size and educational progress during childhood.