Edited sentence: It is a reflection of the reality (bio and non bio) that it is easier to move 1 unit of anything in bulk than to move 1 unit individually.Recent work in physics  shows that the distribution of wealth over the world population is closely correlated with the distribution of the consumption of fuel.The nonuniform distribution (hierarchy) is a natural phenomenon rooted in the physics phenomenon of economies of scale.This connection between physics and economics brings economics along with biology and technology  under the big tent of physics