Estimating the accuracy of geographic variation in indigenous population counts

The ABS 2006 Post-Enumeration Survey was extended to include a sample of localities from the whole of Australia, thereby providing an estimate of census net undercount reflective of the enumeration in remote Indigenous settlements for the first time. The results revealed substantial undercounting of the Indigenous population in certain jurisdictions. At the same time, census counts in many locations were substantially higher than demographic factors could account for. The analytical and policy issues that arise from this revolve around a simple question: what credence can we give to observed spatial patterns of Indigenous population change? This paper seeks to provide an answer by establishing the spatial relationship between population change and net migration at the small area level. This reveals the detailed geography of census undercount and 'overcount' with the former common in remote areas and the latter most evident in regional towns and cities. The findings raise important policy issues about the proper interpretation of Indigenous population change data and the nature of estimates used to determine fiscal resourcing for Indigenous policies and programs.