Demographic projections

The population projections are based on a set of assumptions about the future evolution of mortality, fertility, international migration and internal migration. The FPB also produces household projections that are consistent with the population projections. These types of projections are relevant for various social aspects (e.g. increase in single-parent families or older single-person households) and economic aspects (impact on housing, transport, mobility, consumption, taxation, etc.) of life. Population and household projections are used in many FPB projection models.

Methods and tools

For demographic projections, two models are used:

• The POP model used for the long-term population projections is based on the component method. It is an iterative model which uses fertility, mortality and (national and international) migration assumptions to calculate the population on 31 December of a specific year, using the latest observations by age, sex and nationality. This methodology allows assumptions for each component to be defined and forms an integrated part of the demographic model. The model projects the long-term population (01/01/2071) by age and sex for each district.
• The HPROM model used for the household projections is a static model which breaks down the population projections by age, sex and district, based on the rate at which a position within the household occurs. The positions are defined by the LIPRO typology (Lifestyle Projections), which focuses on the factual situation of individuals and not on their legal situation. The position occurrence rates are not constant over the projection period but are extrapolated by age, sex and district based on the (recent) historical trends, with a saturation effect in the long term.