Abstract: We examine the effects that revenue windfalls from international commodity price booms have on external debt in a panel of 93 countries during the period 1970-2007. Our main finding is that increases in the international prices of exported commodity goods lead to a significant reduction in the level of external debt in democracies, but to no significant reduction in the level of external debt in autocracies. To explain this result, we show that in autocracies commodity windfalls lead to a statistically significant and quantitatively large increase in government expenditures. In democracies on the other hand government expenditures did not increase significantly. We also document that following commodity windfalls the risk of default on external debt decreased in democracies, but increased significantly in autocracies.
Elaborating on PAsinetti (1998), the 'Geometry of Debt Sustainability' - GDS - represents a simple analytical tool for the analysis of the long run sustainability of foreign debt. GDS provides a simple analysis of three aspects of debt sustainability. It points up how the 'structural' aspect - NICA, the non-interest current account - is closely interlinked with the purely 'financial' aspect. The paper focuses on low income countries, LICs, which face several daunting tasks at once: economic growth, human development and regular debt service. Therefore GDS is also used to analyse the 'human development' aspect of debt sustainability. By considering the three aspects together it emerges that there might be a very stringent trade-off between regular debt service and human development expenditures. All the more so because mosto LICs suffer from structural NICA deficits and GDS highlights the fact its improvement is a anecessary condition to achieve long-run debt sustainability. However, export diversification and the building of stronger trading capacities take time. GDS shows why both debt cancellation and additional aid are necessary to give indebted low income economies a chance to improve both human development and long-run economic viability.