Where Does the Sahelian Fertility Transition Stall? Higher-Order Parity Progression in Burkina Faso, Mali, and Niger

Abstract The total fertility rate (TFR), the usual summary of fertility transitions in sub-Saharan Africa, obscures the parity-specific structure of reproductive change. This study asks where in the parity distribution the transition stalls. We use the 2021 Burkina Faso, 2023–2024 Mali, and 2021 Niger Demographic and Health Surveys, covering 44,559 women aged 15–49 years, combining cohort parity progression ratios (PPRs), an exact Shapley decomposition of cross-national gaps in mean parity, life-table PPRs, and discrete-time hazard models fitted to 74,885 parity episodes. Progression through the first three parities was almost identical across countries (cohort PPRs 0.97–0.99). Divergence began at the third-to-fourth transition and widened with each successive parity: the sixth-to-seventh PPR was 0.68 in Burkina Faso, 0.82 in Mali, and 0.89 in Niger. Transitions from parity three onwards accounted for 90.5% of the Burkina Faso–Niger gap and 116.0% of the Burkina Faso–Mali gap. The three countries occupied distinct regimes. In Niger, progression changed little at any parity over two decades. In Mali, the hazard of progression was 15–20% lower than in Niger at every parity, with no parity interaction, consistent with generalised postponement. In Burkina Faso the deficit deepened with parity, from a hazard ratio of 0.67 at the first transition to 0.55 at the seventh, while the median waiting time rose from 37 to 46 months, indicating parity-specific limitation superimposed on postponement. The Sahelian fertility differential is therefore generated among women who already have three or more children, a group largely beyond the reach of adolescent-focused programmes.