Four Brisbanes, Three Sydneys: the Spatial Relatedness of "supercommunities" by Country of Birth in Australian Cities

This study applies spatial relatedness to understand how residential overlaps between two or more groups by country of birth can advance knowledge on community formation in urban space. Based on data over three census periods, we use both pairwise and network analysis measures to identify "supercommunities" composed of multiple migrant groups for the 35 most numerically significant groups by country of birth (34 migrant groups, plus Australia), in Brisbane, Melbourne, Perth, and Sydney. Pairwise analysis reveals both positive and negative spatial relationships driven in part by cultural affinity, while community analysis demonstrates observable spatial regularities between cities demonstrating the presence of supercommunities, which we define as communities of migrant groups from multiple countries whose settlement patterns are bound by spatial homophily from one context to another. The analyses suggest that as cities get larger and migration increases, supercommunities grow in significance and spatial segregation increases, at least in the period immediately following large-scale immigration.