What does the survey entail?
The population forecasts aim to describe the most likely future development of the Dutch population. Three long-term forecasts are made: the Population Forecast, the Key Population Forecast and the Household Forecast. In collaboration with the Netherlands Environmental Assessment Agency (PBL), CBS also makes a Regional Forecast of the number of inhabitants and households per municipality for the medium-term.
The Population Forecast concerns the size and composition of the Dutch population up to 2070. The population count (number of inhabitants by age, sex and migration background) relates to January 1st of the forecast year. The demographic events (birth, death, immigration, emigration) relate to the development during the forecast year. The Key Population Forecast only concerns the population count and demographic events (birth, death, immigration and emigration) by age and sex. The Household Forecast describes the development of the number of households by type (one-person households, couples, single parent household, etc.) and of the number of inhabitants by household position (single, child living at home, etc.). Both households and individuals are further differentiated by age and marital status.
The forecasts describe the ‘de jure’ population of the Netherlands. These are the persons who are included in the municipal personal records databases.
Starting date/year of survey
The first Population Forecast appeared in 1950.
- Population Forecast: every three years.
- Household Forecast: every three years.
- Regional Forecast: every three years.
- Key Population Forecast: twice every three years.
The forecasts follow a three-year publication cycle.
In December, a new Population Forecast appeared. One year later in December the Key Population Forecast and Household Forecast will appear simultaneously. Six months later, the new Regional Forecast will be released. This is followed by a new Key Population Forecast in December of that year.
The Key Population Forecast is an adjustment of the Population Forecast, in which the short-term assumptions are adjusted based on new observations of the subsequent year. This Key Forecast only concerns number of inhabitants by age and sex.
How is the survey conducted
Type of research
Based on analyses of demographic developments, assumptions are made about future trends concerning births, deaths, migration and transitions in household position (divorces, leaving home, etc.). The consequences of the assumptions are calculated in a forecast model.
Checking and correction methods
Forecast figures are checked for internal consistency, for a plausible development in relation to the observations and adherence to the assumptions.
What is the quality of the results?
95% and 67% confidence intervals are published alongside the forecasts. The intervals give an impression of the expected accuracy of the forecast.
Data within one forecast are sequentially comparable in the sense that they are calculated based on the same assumptions. Data for the same forecast year but from different forecasts differ because the figures are calculated with different assumptions and based on different available input data.
Description of quality strategy
The results of the latest forecast are tested annually against new developments. For each new forecast, the assumptions are reviewed and adjusted if necessary. The assumptions are discussed with an advisory committee consisting of independent external experts (the demographic platform).