Spatiotemporal analysis of contraceptive deserts and adolescent fertility clusters in South Asia: A spatial econometric approach to breaking intergenerational poverty cycles

‘Adolescent fertility’ and ‘teenage motherhood’ are key factors that sustain cycles of poverty across generations in South Asia. Yet there is limited research on how these outcomes are geographically clustered and how ‘contraceptive deserts’, areas with very poor access to family planning, affect nearby regions. This study explores: (i) Where are the geographic clusters of adolescent fertility and teenage motherhood? (ii) How do socioeconomic factors shape these outcomes? and (iii) Do contraceptive deserts create spillover effects in neighboring districts? We tested three hypotheses: H₁: Regions with low female literacy and high child stunting have higher adolescent fertility rates (AFR) and teenage motherhood (TMM). H₂: Internet access has a stronger negative effect on AFR than on TMM. H₃: AFR and TMM show significant spatial autocorrelation (Moran’s I > 0.4). To test these, we identified spatiotemporal clusters of AFR and TMM across South Asia and analyzed their drivers using a spatial econometric approach. Specifically, we applied a dual-outcome Spatial Durbin Model (SDM) to panel data from eight South Asian countries (1990–2023), accounting for spatial lags and spillover effects. The findings show three main results. First, female literacy strongly reduces AFR (β = -1.297, p < 0.01), while child stunting increases it (β = 0.495, p < 0.05), confirming H₁. Second, spatial analysis revealed strong autocorrelation (Moran’s I > 0.4) and spillover effects (ρ > 0, p < 0.01), confirming H₃ and the role of contraceptive deserts. Third, persistent hotspots were found in neighboring districts across national borders. However, internet access did not show the expected stronger effect on AFR compared to TMM, rejecting H₂. In conclusion, adolescent fertility and teenage motherhood in South Asia are spatially connected problems, reinforced by localized gaps in education and healthcare. National-level policies alone are insufficient to address these cross-border clusters. Instead, targeted and multi-sectoral strategies in hotspot areas, such as ‘Health Equity Zones’ that improve education, nutrition, and contraceptive access together, are needed to break the cycle of poverty.