The future of global population modeling

Whereas many futures studies begin with the prospect of global over-population, many demographers are equally as concerned about declining population. In order to clarify, and even reconcile, these differences, this paper discusses issues of geographic scale, linkages between populations, and measurement, as well as possibilities for improved forecasts of demographic change. Issues of geographic scale are central to proper analysis, both because there is tremendous variation in fertility, migration, and mortality across the populations, and because of the limitations of techniques of analysis and forecasting. There are many factors that determine demographic change including new waves of international migration, new technologies of reproduction, health and lifestyle, political agendas of demographers and institutions, and even changing definitions of what is human. Continual monitoring of the components of population change is vital in order to achieve an up-to-date demographic outlook. New techniques, in particular, geographic information systems (GIS) and other tools of visualization can aid our understanding of past change, help us to take advantage of new and more reliable data, and realize the implications of current forecasts.