Notes on base data
Base population estimates
The population figures used in the forecasts for 2013 are derived from estimated resident population from Statistics New Zealand. These figures are published at Territorial Area and Urban Area Level, by sex and 5-year age group and at Area Unit Level 5-year aggregated sex at 5-year age group. This allows the extrapolation of population by sex and 5-year age group to Area Units, which are then aggregated to the chosen small area, sometimes splitting Area Units if necessary.
These figures are subject to change or updating from time to time, most notably after census release (usually one to two years after the census is conducted).
Base household estimates
The household estimates used in the forecasts for 2013 were based on age and sex-specific population propensities by different household types. Usual residents’ estimates by Area Unit were extrapolated to Estimated Resident Population and then multiplied by household factors to give estimated 'Resident Households'.
The multiplying factor varies depending on the household type (and the area), such as a factor of 1 for persons living in lone person households to 0.5 for an adult in couple families with dependent households. Children and other dependents, such as elderly parents, are not assumed to 'form' households.
- Statistics New Zealand, 2013 Census of Population and Housing.
- Statistics New Zealand, Population Estimates at 30 June 2013.