Abstract
Population biologists and comparative animal behaviorists assume that competition between members of the same species allocates resource utility, but they cannot validate that assumption without a unidimensional measure of resource utility such as money, which they do not have since they leave humans to the social sciences. One of the social sciences, economics takes the point of view that pervasive zero-sum competition between people does not determine wage andsalary incomes. The present article validates the assumption of populationbiology and comparative animal behavior that competition within a species allocates resource utility by finding the statistical signature of pervasive zero-sum competition in longitudinal data on individual wage and salary incomes.