Data sources are as follows.
| Variable |
Source(s) |
| Population |
U.S. Census (1950-2015); World Population Growth History, Vaughn Aubuchon, A Concise History of World Population, 3rd Ed., Massimo Livi-Bacci (10000 B.C. - 1940 A.D.) |
| Ecological Footprint |
Global Footprint Network (1961-2013); constructed from multiple sources (10,000 B.C. - 1960 A.D.) |
| Gross World Product |
Gross World Product, 1950-2011 - Earth Policy Institute |
| Life Expectancy |
U.S. Census (1950-2015); multiple sources (10,000 B.C. - 1940 A.D.) |
| Median Age |
U.N. Population Division, World Population Prospects: The 2017 Revision. |
| Wealth |
Credit Suisse Research Institute, Global Wealth Report 2017 and Global Wealth Dtabook 2017. |
| Happiness |
Derived from ecological footprint statistics. See Happiness Approximation. |
| Money Inflation |
Inflation in U.S. dollars is relative to the value in 2010, and is modeled based on data from 1950-2017, verifiable from several sources such as the Inflation Calculator app by Brian D'Alessandro. |