Convergence Analysis of Food Security among Sub-Saharan African Countries: Evidence from a Nonlinear TAR Panel Unit Root Test

Technological progress and policy support have improved food security globally, yet Sub-Saharan Africa still faces severe disparities. This study examines food security convergence across 36 countries from 1991 to 2023 using the Threshold Autoregressive panel unit root test to capture non-linear dynamics. Results show regime-specific convergence: Malawi leads among low-income countries (converging in expansionary regimes), Lesotho among lower-middle-income countries (converging in both regimes), and Namibia among upper-middle-income countries (converging in contractionary regimes). These patterns highlight the importance of tailored agricultural and food policies to foster regional convergence and reduce structural inequalities in Sub-Saharan Africa.