Bongaarts Proximate Determinants

The Bongaarts framework of the proximate determinants of fertility decomposes a population's fertility into a biological maximum reduced by a small set of directly fertility-inhibiting factors: the proportion of women in sexual unions, contraceptive use, induced abortion, and postpartum infecundability. By expressing observed fertility as total fecundity multiplied by four indices between zero and one, it quantifies how much each behavioural and biological channel suppresses fertility below its potential ceiling.