A standard source is Angus Maddison’s work, e.g., his book, The World Economy: A Millennial Perspective.
http://www.ggdc.net/maddison/oriindex.htm
Here is a quote from the website:
“Over the past millennium, world population rose 22–fold. Per capita income increased 13–fold, world GDP nearly 300–fold. This contrasts sharply with the preceding millennium, when world population grew by only a sixth, and there was no advance in per capita income.”
“From the year 1000 to 1820 the advance in per capita income was a slow crawl — the world average rose about 50 per cent. Most of the growth went to accommodate a fourfold increase in population.”
“Since 1820, world development has been much more dynamic. Per capita income rose more than eightfold, population more than fivefold.”
“Per capita income growth is not the only indicator of welfare. Over the long run, there has been a dramatic increase in life expectation. In the year 1000, the average infant could expect to live about 24 years. A third would die in the first year of life, hunger and epidemic disease would ravage the survivors. There was an almost imperceptible rise up to 1820, mainly in Western Europe. Most of the improvement has occurred since then. Now the average infant can expect to survive 66 years.”
“The growth process was uneven in space as well as time. The rise in life expectation and income has been most rapid in Western Europe, North America, Australasia and Japan. By 1820, this group had forged ahead to an income level twice that in the rest of the world. By 1998, the gap was 7:1. Between the United States and Africa the gap is now 20:1. This gap is still widening. Divergence is dominant but not inexorable. In the past half century, resurgent Asian countries have demonstrated that an important degree of catch–up is feasible. Nevertheless world economic growth has slowed substantially since 1973, and the Asian advance has been offset by stagnation or retrogression elsewhere.”
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