What Explains Developing Country Growth?
Among developing countries, there was no gross relationship between real income per capita in 1960 and subsequent growth in per capita income. However, once other significant influences, such as education, changes in labor force participation rates, inflows of foreign investment, price structures, and fixed investment ratios are taken into account, the lower the 1960 income level, the faster the income growth. This "conditional" convergence was particularly strong among the poorest half of the developing countries, contradicting the idea of a "convergence club" confined to relatively well-off countries. Inflows of direct investment were an important influence on growth rates for higher income developing countries, but not for lower income ones. For the latter group, secondary education, changes in labor force participation rates, and initial distance behind the United States were all major factors.
"What Explains the Growth of Developing Countries" in William Baumol, Richard Nelson and Edward Wolff, eds., Convergence and Productivity: Cross-National Studies and Historical Evidence, Oxford, Oxford University Press, 1994