Internal migration, year ended June 2017, by TALB cartogram, July2018
In New Zealand, internal migration is typically the most difficult component of net migration’s contribution to subnational population change to measure. Internal migrants are not required to register their moves with any agency. The five-yearly census of population and dwellings has included a question on “usual residence five years ago” since 1971, which has been the authoritative data source for measuring internal migration. However, the infrequency of the collection (every five years), and the ‘snapshot’ nature of a transition-based measure are significant limitations. Other measures of annual subnational population change, such as the Treasury’s Insights tool, provide estimates of internal migration flows between TAs by using linked administrative data. Their approach identifies a set of decision rules for assigning location to individuals, based on a quality assessment of a wide range of address sources in the IDI (Where we come from, where we go). The TA location transitions provide the basis for deriving statistics of annual internal migration as demonstrated by the Insights tool. The data published with this report is the first series we’ve created by estimating all internal migration flows using a movement-based approach. From individuals’ unique address notification histories in key data sources, the paired origin and destination locations defined individuals’ movements. Traditionally, we combined change of address data from a range of administrative sources with other information on international migration to produce estimates of net migration for broad subnational areas. Now, we can derive direct estimates of movements from address histories from the anonymised unit record information of address notifications in the IDI. This gives a better understanding of people’s movements within New Zealand.Internal migration information is of great interest to local and central government, businesses, and communities. Churn and turnover of populations at local area level is one of the contributors of subnational population change, in both size and characteristics.
This layer was created by joining the internal migration table (CSV) to centroids of the TALB cartogram. The map associated with this was produced by using a hexagon symbol resized to fit the map.