Multi-regional projection models are amongst the most conceptually sophisticated and highly-regarded models for producing subnational population projections. But they can present a number of challenges in real-world applications, especially when the number of regions is large and regional populations are small. Data requirements become huge, demographic patterns become ‘noisy’ and unstable, considerable data estimation and smoothing is necessary, and a large number of assumptions have to be formulated. All of this consumes substantial amounts of money and staff resources. This chapter describes projection software which attempts to simplify and lower the costs of the projections process without compromising on the principal strengths of the multi-regional approach. POPACTS (POpulation Projections for rural Areas, Cities and Towns of a State) is new Excel/VBA software which enables projections to be produced for a State, up to 15 large sub-State regions and a flexible number of local areas. Local area projections can either be demography-led or dwelling-led. The projections process is simplified by using five year age groups, reducing the fully multi-regional model by applying multi-bi-regional structures, and adjusting directional migration probabilities via scaling to assumed net migration totals. In addition, users are able to select pre-loaded options for projection assumptions, or set their own, and Excel’s capacity for visualisation is applied to facilitate the review of projection outputs for plausibility. Illustrative projections for New South Wales and its local government areas are presented.
|Title of host publication||Demography for Planning and Policy|
|Subtitle of host publication||Australian Case Studies|
|Editors||Tom Wilson, Elin Charles-Edwards, Martin Bell|
|Place of Publication||Switzerland|
|Number of pages||17|
|Publication status||Published - 2016|
|Name||Applied Demography Series|