Internal migration in the Norwegian projection model

Helge Brunborg, Statistics Norway
Inger Texmon, Statistics Norway
Kjetil Sørlie
Nico Keilman, University of Oslo

The population projections for Norway are based on aggregating projections for Norway's 431 municipalities. The municipal population sizes range from 250 to 500,000 inhabitants. An important challenge for the projections is the centralisation of the Norwegian population, which the projection model is not fully able to project far into the future. Several attempts have been made to tackle this problem: First, changing the model for internal migration from a migrant pool model to a matrix model based on gross flows between regions of origin and destination. Second, experimenting with different lengths of the observation period for the migration parameters, based on contra-factual historical projections with observed fertility, mortality and international migration parameters but with different historical patterns for internal migration. Third, studying migration to and from central regions in a life-course perspective. The forecast errors connected to the improved model were lower than those for the old model, especially for regions with low or negative growth rates, but not yet as low as expected.