A critical review of Bongaart's aggregate model and development of an index as a suggestive measure.
Total fertility rate (TFR) is age standardized. Variations in TFR cannot be explained by variations in age structure. Bongaarts Aggregate Model explained variations in crude birth rate by variations in age structure. However, that measure does not reflect true picture. This paper highlights that and also as a suggestive measure develops an index, which can be used in studies of fertility transition and fertility differentiates. (author's)