The impact of education-bound mobility on inter-regional migration age profiles in Australia

Research on internal migration age profiles is important for understanding the dynamics of a country’s population geography, creating accurate population estimates in non-census years, and smoothing migration age profiles for sub-national population projections. In the international literature, internal migration age profiles are often characterised as relatively stable over time and space, and consisting of gradual changes in migration intensities from one age to the next – as depicted by the widely-used model migration schedule. However, a few migration age profiles in Australia are known to exhibit highly age-specific ‘spikes’ related to movement to higher education institutions. This paper undertakes an investigation of inter-regional migration age profiles in Australia to determine the extent of the phenomenon. Data from the Australian 2011 Census are used to create inter-regional migration probabilities by single years of age, together with more specific probabilities describing university-bound and boarding school-bound migration. Migration age patterns at three spatial scales of region are examined. It is shown that university-bound age-specific spikes are present in the majority of regional in- and out-migration age profiles in Australia at either age 18 or 19. In many cases this results in the peak migration probability occurring at these ages. Boarding school-bound migration is less significant and present in a smaller proportion of regional migration age profiles. In preparing smoothed migration age profiles for sub-national population projections it is imperative to smooth out noise but retain these significant education-bound migration spikes. Further work is required to determine the optimum ways of smoothing these migration age profiles.