Global Projections of Household Numbers Using Age Determined Ratios

Abstract

A new method based upon age determined population ratios is described and used to estimate household population intensities (households per person). Using an additive and a bounded model household projections are given to 2050 for the world and to 2030 for seven fertility transition subgroups (cohorts) of the countries of the world. Based upon United Nations 2002 Revision data, from an estimated 1.56 billion households at 2000, household growth to 2030 is projected to be an additional 1.1 billion households, whether population increase is 1.3 billion persons under the United Nations low fertility variant or 2.7 billion persons under the high fertility variant. At that date over one third of all households are projected to be Chinese or Indian. By 2050 it is projected that there will be 3.3 billion households with a 95 per cent confidence interval on modelling error only of ± 0.5 billion. This compares with 3.2 billion in the Habitat: Global Report on Human Settlements 1996. The apparent similarity of total household growth under various scenarios conceals a wide range in the growth of household intensities across fertility transition cohorts. It is suggested that models, projections and error be reviewed biennially and that household and population projections be produced jointly.Household projections, world, age ratios, fertility