Every year in February Statistics Denmark provides DREAM with updated data regarding immigration, emigration, live births, deaths and change in citizenship, which can be broken down by gender, age and ancestry. It is then DREAM who run the actual projection model for the whole of Denmark. Statistics Denmark and DREAM discuss the assumptions in the model regarding migration, fertility and mortality in order to assess whether changes in methodology are necessary. When the model is declared ready, DREAM provides Statistics Denmark with data. These data are both the foundation for the published statistics for the projection for the entire country as well as important background data for the regional models, which Statistics Denmark run.
Statistics Denmark has made population projections since 1963. In the beginning it didn´t happen on an annual basis. With few exceptions annual projections has been made since 1978. Often several scenarios have been published. Now only one scenario is made with one set of assumptions.
From 2010 and onwards Statistics Denmark has made the projection for the entire country in cooperation with DREAM. The methods in the new common model were primarily based on DREAM´s former projections. DREAM´s experience with more advanced methods within eg mortality was an important reason why the common projection is based on DREAM´s former projection. On DREAM's website there is thorough description in Danish of the methods within all the areas of the projection.
Statistics Denmark makes an annual population projection for Denmark in cooperation with the research institution DREAM. From a given set of conditions and assumptions Denmark´s future population is calculated and broken down by gender, age and ancestry.
Based on the projection for the entire country Statistics Denmark makes a regional projection which can be broken down by gender, age, province and municipality. The projection by provinces and municipalities are not broken down by ancestry.
As a part of the projection, results are also available regarding changes in population concerning live births, deaths, immigration and emigration
The projections are based on historical data about the population broken down by sex, age and ancestry as well and fertility, mortality and migration.
Assumptions about fertility, mortality and migration are also necessary in order to make the projections.
The projections are made once a year with the population 01 January as starting point (or jump-off population). They are published in the beginning of May.
In total three projections are made. One for the entire country, one for the 11 provinces (landsdele) and one for the 98 municipalities (kommuner).
The projection for the entire country is made in cooperation with DREAM and constitute the population foundation for DREAM´s economic projections.
The projection broken down by municipalities are also used extensively by municipalities and often forms the basis for the municipalities' own projections. These local projections often include a number of local factors, which are not included in DST’s projection. DST’s projection also has great interest in local media across the country.
The uncertainty concerning the future number of live births, deaths, immigration and emigration - as a result of unexpected changes in the assumptions of the projection about fertility, mortality and migration - must be considered as giving rise to the most significant deviations between the projection and the actual development.
The population projection is deterministic and not stochastic. There is only one scenario and probabilities on different outcomes are not calculated.
The statistic was published on time.
Each projection is a new statistics and is not meant to be used with former years projections.
In 2010 Statistics Denmark made a common projection with DREAM for the first time. With the new common projection the projection model was changed. The new model was primarily based on DREAM´s former model.
These statistics are published in a Danish press release and in the StatBank under Population projections.