Suppose that all people in the world are allocated only two characteristics over which they have (almost) no control: country of residence and income distribution within that country. Assume further that there is no migration. We show that more than one-half of variability in income of world population classified according to their household per capita in 1% income groups (by country) is accounted for by these two characteristics. The role of effort or luck cannot play a large role in explaining the global distribution of individual income.

We would expect that the process of globalization between 1870 and 1914 and subsequent disintegration of the world economy during the interwar period would have led first to income convergence and then to income divergence between the participating countries. But in fact we find stronger evidence for income convergence during the interwar period than during the first globalization. Similarly, the average level of import protection in the world cannot be shown to have either helped or hampered convergence. The evidence for trade-induced convergence is therefore weak.