THE POVERTY of sub-Saharan Africa is one of the most obdurate features of the world economy. Since the industrial revolution, this has been the world's poorest and also its most slowly growing region. The most reliable estimates of world and regional gross domestic products for the period 1820-1992 are those prepared by Angus Maddison. Figure 1 shows estimated long-term growth profiles for selected regions. According to these estimates, sub-Saharan Africa (hereafter, Africa) began the modern era at approximately one-third of the income level of the richest region at that time, Western Europe. In 1992 it had approximately one-twentieth of the income level of the richest region, Maddison's "western offshoots," which includes the United States, Canada, Australia, and New Zealand. Maddison estimates that Africa's per capita income in 1992 was approximately that of Western Europe in 1820: $1,284 in Africa compared with $1,292 in Europe, in purchasing power parity (PPP) 1990 international dollars. Although this is only a gross approximation, it highlights the extent of Africa's economic plight.