Modeling fertility by order of birth

Although the modeling of age specific fertility schedules has been exposed in a lot of researches, modeling fertility by birth order has received little attention. Several works have attempted to fit observed parity specific schedules, but none of them expands to models that could be used to estimate parity specific schedules when only data on all births combined fertility are available.

We propose to derive parity specific fertility rates from an overall age-specific (all births combined). Based on model proposed by Peristera and Kostaki for fitting fertility curves, we explore the assumption that there is a relationship between all the parameters of their model for all births combined and for parity specific, and derive several sets of coefficients to estimate age and parity specific fertility schedules from age and all birth combined fertility schedules.