6.1 Population change factors

The changes occurring in the population are viewed by means of population change factors. Population changes are births, deaths and migration (changes of domicile). In migration internal migration and international migration (immigration and emigration) are separated, the latter of which refers to migration over the borders of the country. The above population change factors have a direct effect on the development of population size. In demography births and deaths are also known as so-called natural population changes (vital events).

Other population change factors are marriages contracted and divorces.

The population change factors affect the development of population size in different ways. Births increase the population while deaths decrease it. However, changes of domicile influence the development of population size, on one hand, by enlarging it when moving to a new domicile, and, on the other hand, by reducing population size when moving away from a certain domicile.