Simple measures of convergence in per capita GDP: a note on some further international evidence

We apply simple measures of convergence in per capita GDP, namely, the trends in the coefficient of variation (sigma-convergence) and rank concordance (gamma-convergence), for the period 1960-92 to a wide group of countries which are classified using the World Bank typology. The findings indicate sigma-convergence, albeit at a slow rate, for 'High Income' and 'Upper Middle Income' countries, very slow to negligible convergence for 'Lower Middle Income' countries and divergence for 'Low Income' countries. Our results also suggest several periods for all country categories when sigma-convergence is constant. However, since we do not find gamma-convergence during these episodes, we conclude that beta-convergence is not demonstrated. The rank concordance measure emerges as significant only from about the late 1980s, save in the case of 'Low Income' countries where 'leap frogging' is observed from about 1981. The implications of these results for the neoclassical growth model are discussed.