Un réexamen de l’effet de seuil de la dette publique sur la croissance économique en Afrique subsaharienne[A reevaluation of the threshold effect of public debt on economic growth in Sub-Saharan Africa]

Our study aims to reexamine the relationship between public debt and economic growth in Sub-Saharan African countries over the period from 2000 to 2020. To achieve this, we have chosen to use a dynamic panel threshold model, recently developed by Seo and Shin (2016), to address various estimation issues, including reverse causality and endogeneity. Furthermore, differences among Sub-Saharan African countries in terms of development level, natural resource intensity, institutional quality, and the level of illicit financial flows are examined. The results reveal a U-shaped relationship between public debt and economic growth, indicating the existence of an optimal level of public debt at 58% of GDP for the entire sample. For the group of countries characterized by more developed economies, rich in natural resources in the region with a satisfactory Human Development Index (HDI), relatively better institutional quality, and higher illicit financial flows, a debt threshold of 74% is estimated. In contrast, for the group of countries characterized by lower dependence on natural resources, a lower HDI, less favorable institutional quality, and lower illicit financial flows, a debt threshold is estimated at 47%, significantly lower. These results highlight the diversity of optimal public debt thresholds based on the specific characteristics of Sub-Saharan African countries.