Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Estimates of growth rates of real output per head in various countries are presented and it is concluded that divergence has been more common than catch-up in the twentieth century. Trends in the Human Development Index are reported and these offer a more encouraging picture of the relative performance of poor countries. Key issues in growth economics are reviewed against the background of the long-run evidence; these include the plausibility of innovation-based theories of endogenous growth, the reasons for the commonplace failure of fast-growing countries to sustain their growth, and the impact of technological revolutions on productivity growth. Copyright 1999 by Oxford University Press.