A curve fit of per capita GDP to footprint yields values of about $250,000 per person for 100 years of life expectancy (7 times the current U.S. value) and $378,000 per person for 100 percent happiness (11 times the current U.S. value). The average of these numbers is the most likely actual value (based on the population-average of the sample countries under current conditions), or $314,000 (9 times the current U.S. value and 27 times the population-average of the sample countries). The average number of people who can be sustained by all available bio-productive land is 203 million people (168 million for life expectancy and 239 million for happiness), or two-thirds of the current U.S. population.
With a population of over 6.5 billion people, the world now has over 32 times the number that can live within the biosphere’s means under ideal conditions. Based on my sample of countries, the average of life expectancy and happiness (what I will in future refer to as the “ideality index,” measured in percent) is 67, or two-thirds of the maximum, with a footprint of over 2 hectares per person (according to the latest Living Planet Report by the WWF; in my sample, it is 2 for life expectancy and 5 for happiness, with an average of 3).