World population, comparison of different historical sources

Among others these are the original source:

McEvedy, Colin and Richard Jones, 1978, "Atlas of World Population History," Facts on File, New York, pp. 342-351.

Biraben, Jean-Noel, 1980, An Essay Concerning Mankind's Evolution, Population, Selected Papers, December, table 2.

Durand, John D., 1974, "Historical Estimates of World Population: An Evaluation," University of Pennsylvania, Population Center, Analytical and Technical Reports, Number 10, table 2.

Haub, Carl, 1995, "How Many People Have Ever Lived on Earth?" Population Today, February, p. 5.

Thomlinson, Ralph, 1975, "Demographic Problems, Controversy Over Population Control," Second Edition, Table 1.

United Nations, 1999, The World at Six Billion, Table 1, "World Population From" Year 0 to Stabilization, p. 5, U.S. Census Bureau (USCB), 2012, Total Midyear Population for the World: 1950-2050.

Michael Kremer (1993) "Population Growth and Technological Change: One Million B.C. to 1990", Quarterly Journal of Economics., August 1993, pp.681-716.

Klein Goldewijk K, Beusen A, Janssen P (2010) "Long term dynamic modeling of global population and built-up area in a spatially explicit way: HYDE 3.1". The Holocene 20:565-573.

HYDE is an internally consistent combination of updated historical population (gridded) estimates and land use for the past 12,000 years. Categories include cropland, with a new distinction into irrigated and rain fed crops (other than rice) and irrigated and rain fed rice. Also grazing lands are provided, divided into more intensively used pasture, converted rangeland and non-converted natural (less intensively used) rangeland. Population is represented by maps of total, urban, rural population and population density as well as built-up area.

Gapminder's population data is divided into two chunks: One long historical trend for the global population that goes back to 10,000 BC. And the second chunk is country estimates that only reaches back to 1800.

For the first chunk, several sources were used. You can learn more at https://docs.google.com/spreadsheets/d/1hkLbEilJbl630IG68q-aQJlUjuTFm9b_12nQMVd1sZM/edit#gid=0. For the second chunk, Gapminder uses UN population data between 1950 to 2100 from the UN Population Division World Population Prospects 2019, and the forecast to the year 2100 uses their medium-fertility variant.

For years before 1950, this version uses the data documented in greater detail by Mattias Lindgren in version 3. The main source was Angus Maddison's data, which CLIO Infra Project maintained and improved. Note that when combining version 3 with the new UN data, the trends for a few countries didn't match up in the overlapping year 1950.

Minor adjustments were made to the years before and after to smooth out discrepancies between the two sources and avoid spurious jumps in Gapminder's visualisations.

Visit https://www.gapminder.org/data/documentation/gd003/ to learn more about the methodology used and the data from back to 10,000 BC.

World Population Prospects 2022 is the 27th edition of the official estimates and projections of the global population that have been published by the United Nations since 1951. The estimates are based on all available sources of data on population size and levels of fertility, mortality, and international migration for 237 countries or areas. More details at https://population.un.org/wpp/Publications/.