Basic Sources, Concepts, Definitions and Types of Measures

What is ‘demography’? A short answer, sufficient perhaps to quickly satisfy the lay inquirer, is ‘the study of human populations’. More elaborate definitions are, however, to be found in the literature. Several are reproduced in Table 1.1, where page references make it clear that it is common for books like this one to commence by addressing the question just posed. Some definitions are more restrictive than others. The Belgian Achille Guillard is credited with having first coined and defined the term ‘demography’. Of the more recent definitions cited, that attributed to the IUSSP advances us a little beyond ‘the study of human populations’, but remains general and non-specific. Hauser and Duncan provide more detail, introducing the notion of ‘territorial distribution’ to provide a touchpoint with geography and itemizing four processes through which populations change over time. Bogue asserts the ‘statistical and mathematical’ nature of demography, adds ‘marriage’ as a fifth process generating change and claims theory-building as a long-run disciplinary goal. Shryock, Siegel and Associates in their encyclopaedic two-volume survey of demographic techniques offer that demography may be defined either ‘narrowly or broadly’, whilst Wunsch and Termote explicitly acknowledge only three processes of change, although their second sentence broadens the agenda á la Shryock et al. Weeks’s definition is a real catch-all, that of Hinde highlights future prediction as an important element of demography, Preston, Heuveline and Guillot are succinct (perhaps too succinct to be very helpful), and Weinstein and Pillai emphasize that demographers deal with aggregates of living individuals. Siegel and Swanson’s definition revises that of Shryock, Siegel and Associates in the earlier edition of The Methods and Materials of Demography.