[Proposal for a model for the desaggregation of demographic projections of large areas into their geographical...

The problem of the preparation of estimates of the total population of geographic subdivisions after the 1980 census is studied with a view to the tabulation on mortality data of Rio de Janeiro State (Brazil) by municipal districts and the estimation of regional mortality rates. In Brazil, the calculation of the official population estimates is undertaken by the Brazilian Institute of Geography and Statistics. The method employed to estimate the population of geographic subdivisions is known as the "AiBi method". This procedure is analysed and an alternative mathematical model is proposed that also satisfies the closure condition, that is, the projected values for the sum of the segments up to the total population projection. As an application of the proposed model, estimates of the population of the municipal districts of Rio de Janeiro State were prepared covering the period from 1981 to 1990.