Demography is the scientific study of human populations. Classical demography has at its core three processes: fertility, migration, and mortality. To be human is to be part of the demographic process, so contemporary studies of population focus not only on the implications of population size and change, but also on how social influences affect individual behaviour and how actions at the individual level contribute to the composition of the population.

Globally, population issues are of increasing concern to governments and other policy-makers. Particularly over the last...