Projections of small-area population dynamic in Austria

Stephan Marik-Lebeck, Statistics Austria
Gustav Lebhart, Statistics Austria

Understanding the varying impacts of demographic changes at the local level is of essential interest for decision making on local level. Projections of future population development can provide a valuable tool by identifying a broad range of perspectives for different aspects of local planning, i.e. the future needs and dimensions of infrastructure. During the past few years STATISTICS AUSTRIA was able to gain experience in conducting small area population projections, using the SIKURS multi-state and multi-component model for regional projections. Currently, work is in progress for a population study for the Vienna City Council based on 262 administrative “traffic-catchment” areas. Though consistent on aggregate level with the latest national population projection, modelling is necessary on micro level and has to take into account the very diverse demographic structure of small geographical units in adopting and modyfying the assumptions. The potential complexity of modelling is greatly reduced by identifying “area types” that represent homogenous units in terms of different demographic components (fertility, mortality and migration). Consequently, for each area type specific sets of assumptions can be applied, allowing for their more concise implementation in the model. This also helps to overcome problems of comparability of different data sources, which have to be used due to the restricted availability of demographic data on micro level. Special emphasis has to be given to migration as its influence on micro level might essentially alter the structure and total number of the population. Also, the foreseeable new housing construction is taken into account by identifying development areas with the prospective number, occupancy rates and demographic structure of housing to be built. The paper presents the main results of the projection for Vienna City Council and also identifies possibilities for further methodological refinements.