ABSTRACT
Population size and change are fundamental aspects of community structure that affect and are affected by local economy, institutions and resources. They influence a community’s ability to provide essential services, support retail and commercial establishments, and give local government and other public institutions sufficient capacity to manage local affairs and plan for the future. Population change comprises two primary components: natural increase (the balance of births and deaths) and net migration (the sum of international and internal exchanges). In both the UK and the US, as rates of natural increase have fallen, the migration component has grown in its contribution to both national population growth and internal population redistribution. This is an important development because the determinants of spatial variability in birth and death rates are quite different from the factors associated with variability in migration. Hence, if maintaining sufficient population to justify public and private investment is a policy goal, 1 interventions designed to promote fertility or enhance longevity differ considerably from those implemented to retain or attract population via migration.
