Demography

Demography is the study of the change in the size, density, and composition of human populations over time, and includes analysis of such factors as birth rates and death rates, as well as emigration and immigration.

"The word ‘demography’ was first used in 1855 by a Belgian, Achille Guillard, and in his terms the study included many aspects of humans including general movement and progress (including morals) in civilized countries. He used the vital statistics of birth, marriage, sickness and death from census and registration reports." (reference for quote:Thomas A Ebert, Oregon State University, Corvallis, Oregon, USA:Demographic Concepts in Encyclopedia of Life Sciences. Copyright © 2006 John Wiley & Sons, Ltd.)