Lant Pritchett discusses the significant divergence in per capita incomes between developed and developing countries over the past 150 years. From 1870 to 1990, the ratio of incomes between the richest and poorest countries increased by about five times, and the income gap between the richest country and all others grew by an order of magnitude. This divergence is attributed to different long-term economic performance patterns of two groups of countries: the developed or advanced capitalist countries, which include Europe, Japan, and their offshoots, and the developing or less developed countries, which have generally grown more slowly. The developed countries have shown strong convergence in per capita incomes, with poorer members growing faster than richer ones. However, within the developing countries, there have been varied growth patterns, with some converging rapidly while others stagnate or decline. The paper uses data from Maddison (1995) to show that the growth rates of developed countries have been remarkably similar, with a narrow range of growth rates over the 1870–1960 period. The growth rates have remained stable over time, with the average growth rate of 17 developed countries between 1980 and 1994 being almost the same as between 1870 and 1960. To estimate the lower bound of per capita GDP in 1870, the author concludes that $250 (in 1985 purchasing power equivalents) is the lowest possible level. This is based on historical data, subsistence income calculations, and caloric intake estimates. Using this lower bound, the author calculates that the ratio of per capita incomes between the richest and poorest countries has increased significantly, from 8.7 in 1870 to 45 by 1990. This indicates substantial divergence in income levels over the past 150 years. The paper also highlights the variability in growth rates among developing countries, with some experiencing rapid growth and others stagnation or decline. The growth rates of developing countries have been lower than those of developed countries, leading to a significant divergence in per capita incomes. The author argues that while there may be potential advantages to being behind the technological frontier, historically, such cases are rare. The paper concludes that economic growth and development require addressing four key questions: what drives growth in leading countries, what enables countries to catch up, why some countries fail to grow, and why some remain in low growth for long periods. The findings suggest that economic growth is highly variable and that policies must be tailored to specific situations.Lant Pritchett discusses the significant divergence in per capita incomes between developed and developing countries over the past 150 years. From 1870 to 1990, the ratio of incomes between the richest and poorest countries increased by about five times, and the income gap between the richest country and all others grew by an order of magnitude. This divergence is attributed to different long-term economic performance patterns of two groups of countries: the developed or advanced capitalist countries, which include Europe, Japan, and their offshoots, and the developing or less developed countries, which have generally grown more slowly. The developed countries have shown strong convergence in per capita incomes, with poorer members growing faster than richer ones. However, within the developing countries, there have been varied growth patterns, with some converging rapidly while others stagnate or decline. The paper uses data from Maddison (1995) to show that the growth rates of developed countries have been remarkably similar, with a narrow range of growth rates over the 1870–1960 period. The growth rates have remained stable over time, with the average growth rate of 17 developed countries between 1980 and 1994 being almost the same as between 1870 and 1960. To estimate the lower bound of per capita GDP in 1870, the author concludes that $250 (in 1985 purchasing power equivalents) is the lowest possible level. This is based on historical data, subsistence income calculations, and caloric intake estimates. Using this lower bound, the author calculates that the ratio of per capita incomes between the richest and poorest countries has increased significantly, from 8.7 in 1870 to 45 by 1990. This indicates substantial divergence in income levels over the past 150 years. The paper also highlights the variability in growth rates among developing countries, with some experiencing rapid growth and others stagnation or decline. The growth rates of developing countries have been lower than those of developed countries, leading to a significant divergence in per capita incomes. The author argues that while there may be potential advantages to being behind the technological frontier, historically, such cases are rare. The paper concludes that economic growth and development require addressing four key questions: what drives growth in leading countries, what enables countries to catch up, why some countries fail to grow, and why some remain in low growth for long periods. The findings suggest that economic growth is highly variable and that policies must be tailored to specific situations.