The literature on inequality among economies has focused on analysing the dispersion of indicators such as annual per capita income. This paper adopts a different approach, as it considers the life cycle dimensionof inequality, life expectancy and whether annual per capita income can be expected to converge or not in the future.

The determinants of inequality in permanent income are analyzed, as are the determinants of the differences between inequality in annual and permanent income. Finally, various simulations show that those differences can be very significant, justifying the usefulness of this kind of approach.