In Search of an Economic Quantum In the World Economy.

Considering the World Gross Domestic Product WGDP as a representation of all the production by humankind, is it possible to define a smallest common quantitative measure, an «economic quantum» at an individual level, whose aggregate will lead to the word GDP ?

Is this economic quantum the GDP by an individual, produced using his sole physical forces of some 180 kWh/year ? Or is this «economic qu...