a shift in the population such that the older age groups grow in size relative to the younger age groups. This leads to a rise in the average age in the population.
the part of the population which was born in the same year or the same years.
births per 1,000 residents. When calculating the natural population balance per 1,000 residents, the mortality rate is subtracted from the birth rate.
collective name for the demographic effects attributed to changes in the birth and mortality rates. For industrialized countries, this refers to the aging of the population and possibly a population decline resulting from low fertility and high life expectancy.
the time lag between changing demographic processes, e.g. decreasing fertility, and the point when the effects of these processes are experienced. The effects of a decline in fertility will not be felt in the labor market until after twenty years, when the respective, smaller birth cohorts reach the employment age.
a theoretical assumption regarding a typical historical transition sequence from high birth and mortality rates to low birth and mortality rates. During the transition the population growth rises initially, but then falls back to a low level. This simplified model is based on past observations made in the current industrialized countries.
level of procreation of a population. The level of fertility can be measured, for instance, in births per 1,000 residents (birth rate) or in the number of children per woman (total fertility rate).
Life expectancy (at birth):
a hypothetical measure for how long a person will probably live if born in a particular year, assuming that as this person ages, he or she will have the same probability of dying that people have at that age today.
the difference between immigration and emigration.
the number of deaths per 1,000 residents. When calculating the natural population balance per 1,000 residents, the mortality rate is subtracted from the birth rate.
Natural population balance (or natural balance):
the difference between births and deaths.
Person with an immigrant background (in Germany):
all immigrants who have lived in the current German Federal Republic since 1949, as well as all non-citizens born in Germany, and all Germans with at least one parent who was an immigrant or born in Germany as a non-citizen (the Federal Statistical Office’s definition in the context of micro-census analysis).
populations change according to their births and deaths as well as their immigration and emigration. These factors are interdependent and follow short-term and long-term trends in reaction to changing conditions.
sum of natural and migration balance. The basic equation for population is: population in the following year = population in the current year plus births minus deaths plus immigration minus emigration.
Replacement fertility rate:
the number of births necessary in order to completely replace the parent generation. A prerequisite is an average of one daughter per mother. Since not all newborns reach adulthood, the replacement fertility rate depends upon the mortality rate and actually demands more than one daughter. Measured by the total fertility rate, the replacement fertility rate in modern industrialized countries is approximately 2.1 births on average (boys and girls combined).
a higher possibility that a particular population group will migrate than others. Young and educated people tend to migrate more often.
Total fertility rate (TFR):
a hypothetical measure indicating how many children a woman will have during her reproductive phase, assuming that over this timespan in each year she will have the same probability of giving birth as women have at the respective age today.
This text is part of the policy brief on Interner Link: "Demographic Change and Migration in Europe".