Population change is the number of people living in an area. There are two types of Population change – Natural Change (number of deaths per thousand against the number of live births per thousand) and Migration (the movement of people into or out of an area or country). Natural change depends on the balance between the birth rate and the death rate if there is more births than deaths this means a population increase and if there are more deaths than births this means a population decrease. Net Migration (the balance between immigration and emigration), net in-migration (if there is more immigration than there is emigration the population will increase), net out-migration (if there is more emigration than immigration then the population will decrease).
Migration is only one of two different types of population movement, with migration, a change of address is involved. However, that change must last at least a year. There are three forms of circulation (where a you move to a temporary location for less than a year) shopping, commuting and taking a holiday. There are also three different types of circulation:
- Daily – e.g. shopping, commuting
- Weekly – e.g. longer-distance commenting, holidaymaking
- Seasonal – e.g. going away to university, UK pensioners spending a summer in Spain