Indeed, if people are not interested in demographic phenomena, they are not interested in themselves. It is clearly a discipline because it is a field with its own body of interrelated concepts, techniques, journals, departments, and professional associations. Demography is also an interdisciplinary field because it draws its subject matter and methods from many disciplines, including sociology, economics, biology, geography, history, and the health sciences. Finally, demography is also considered a subdiscipline within some of these same major disciplines. In most universities, demography courses are taught within the sociology curriculum, perhaps because population phenomena have so long been linked to social processes.
Populations are never static.
If some groups within a population grow or decline faster than others, the composition of the whole is altered. It is not a comprehensive treatment of the subject, but it does provide an overview of demographic processes and the basic measures used to assess them. In addition, it traces population trends in the world and the United States, surveys the demographic differences among population groups, and examines broad social issues linked to population change. The first three sections of this Bulletin provide the framework for studying the dynamics of population. Fertility, mortality, and migration are at the root of all demographic change.