DISTRIBUTIONS USING AGE RATIOS AND THE POISSON DISTRIBUTION.

Global projections are made for household numbers and size distributions in 2010, 2030 and 2050. These projections are assembled from 142 individual country projections and a ‘rest of world ’ projection. These projections use the latest UN World population projections with three fertility scenarios (UN 1999) and the “Age ratio-Poisson ” model originally developed in Jennings, Lloyd-Smith and Ironmonger (1999), as a “Dependency ratio-Poisson ” model. The projections show the total world growth in household numbers is almost independent of the fertility scenario. If these projections are sustained, in the next 50 years, the world number of households will almost treble from 1.3 billion in 1990 to 3.6 billion in 2050. This will occur whether the world population doubles from 5.1 billion to 10.4 billion on the high fertility scenario or only increases by 50 per cent to 7.1 billion on the low fertility scenario. The apparent similarity of total household growth under the various scenarios conceals a phenomenal switch in the size distributions. Urban regions are expected to absorb most of this growth. The paper continues the research on the demography of households by the University of Melbourne’s Households Research Unit