A methodological note for local demographic projections: A shift-share analysis to disaggregate official aggregated estimations.

Abstract

Population projections are used as a common framework to orientate different policies and planning in several fields including public retirement systems, health care and education. They would be also needed for the urban planning as well as for other local policies such us social services but these projections are usually made at a certain level of spatial aggregation, national level or large regions but they are rarely are calculated at the local level. In this note a simple procedure, based in Shift-Share analysis, is proposed as a possible way to approximate local projections from official estimations. It allows us to estimate the future size and age structure of the population at a more disaggregated level, local-level, getting data consistent with those produced at national and regional level by the official institutions. These data come to be a valuable source of information in the design of local policies, especially for those concerned to urban and housing planning.