PRESENTING THE DATA
OUTPUT CATEGORIES
Levels of aggregation
The components of income can be aggregated in a hierarchy to produce selected measures of income for particular analytical purposes. Gross and disposable income are the main income measures produced.
Total or gross income is the sum of income from all sources before income tax, the Medicare Levy and the Medicare Levy Surcharge are deducted. It is the most commonly used measure.
Disposable income is derived by deducting taxes on income (where this information is available or can be imputed) from gross income.
Measures of income distribution
Quantiles
The preferred output categories for income statistics divide the population into quantiles. Income quantiles are derived by ranking persons (or any other units) from the lowest to the highest on the basis of their income (including units with zero or negative incomes). When the population is divided into five equally sized groups, the quantiles are called quintiles. Thus, the first quintile will comprise the first two deciles and the first 20 percentiles. In other words, the 20 percent of persons (or other units) with the lowest incomes.
Equivalised income
The household level is generally the preferred statistical unit for income distribution analysis. However, larger households normally require a greater level of income to maintain the same material standard of living as smaller households, and the needs of adults are normally greater than the needs of children. It is therefore recommended for most purposes that household income estimates are adjusted by equivalence factors to standardise them for variations in household size and composition, while taking into account the economies of scale that arise from sharing a dwelling. The resulting estimates are known as 'Equivalised household income'. Equivalisation can be applied to any aggregate household income measure.
When 'Total household income' is adjusted according to an equivalence scale, it can be used for comparing the situation of households as well as comparing the situations of individuals.
Refer to the standard for Equivalised household income for more information.