SYNTHETIC INCOME ESTIMATES IN NON-SURVEY YEARS
The Analytical Services Branch is currently involved in a project investigating methodological possibilities for producing income data at unit record level in years when the Australian Bureau of Statistics (ABS) will not be running a Survey of Income and Housing. The project is divided into two phases. Phase 1 involves exploring and testing possible methods for producing synthetic income microdata using historical data. Conditional on sound methodology being identified in Phase 1, Phase 2 of the project will then proceed to produce synthetic income microdata for non-survey years.
The static ageing techniques of microsimulation models are being explored as a possible method for producing synthetic income microdata. Such ageing techniques allow for the updating of sampling weights and income to more closely reflect target year conditions, using external benchmark data. New sampling weights for each unit record are obtained by adjusting original unit weights in line with movements over time in the characteristics of the populations (such as demographic, labour force status) that the record represents. New income levels for each unit record are obtained by indexing (either inflating or deflating) income from different sources by applying appropriate uprating factors that more closely reflect movements in that component of income in the economy over time (such as changes in wages/salaries, social security payments, consumer price index etc).
Preliminary results from the exploratory study were discussed at our Methodology Advisory Committee in November. Suggestions were made for further refining of the population weights and greater scrutiny over the choice of uprating factors for the income variables.
For more information, please contact, Anil Kumar on (02) 6252 5344