How reliable are Indigenous population projections?

Projections of Australia’s Indigenous population are used in a wide range of planning, service provision, policy development, and research activities. But apart from a very general sense that Indigenous population data are imprecise, little is known about the reliability of these projections. This paper evaluates several past sets of ABS Indigenous population projections. It addresses the question ‘How well did past ABS Indigenous projections predict the Indigenous Estimated Resident Populations (ERPs) five years later?’ Past ABS projections of the Indigenous population are assessed against subsequent ERPs using Percentage Discrepancy measures. Both total and age-specific populations are evaluated. The results show that ABS Indigenous projections have generally not predicted the next census year’s ERP very well, with the exception of the Northern Territory. Users should be prepared for the large levels of discrepancy revealed in this study for past projections to be repeated with the most recent set of Indigenous projections.