The concepts of sigma-convergence, absolute beta-convergence and conditional beta-convergence are discussed in this paper. The concepts are applied to a variety of data sets that include a large cross-section of 110 countries, the subsample of OECD countries, the states within the United States, the prefectures of Japan, and regions within several European countries. Except for the large cross-section of countries, all data sets display strong evidence of sigma-convergence and absolute beta-convergence. The cross-section of countries exhibits sigma-divergence and conditional beta-convergence. The speed of conditional convergence, which is very similar across data sets, is close to 2 percent per year. Copyright 1996 by Royal Economic Society.