You'll find man has always accounted for things, its perfectly natural to do so, as it helps you understand how much resources you need to feed and clothe your population.
Economics - well we survived without it until Adam Smith came along, and there are so many competing theories in economics (Austrian, Keynesian, Chicago), its hard to take it seriously, given they can't all be right. Its a pseudo-science, a bit like reflexology. But if it keeps happy those who like maths, but were not good enough to study maths or physics at university, then its a good thing.