New Zealand Atlas of Population Change

Internal Migration (Arrivals and Departures) by Territorial Authority for the population aged 65+ years

These maps are based on the Census Usually Resident Population Count (CURP). Numbers and percentages thus differ slightly to counts based on Estimated Resident Population (ERP), such as net internal and net international migration which have been modelled at ERP level).¹

The territorial authority area maps illustrate where each of New Zealand’s 67 territorial authority area’s internal migrants aged 65+ years came from (Internal Arrivals), and went to (Internal Departures), based on the Census question ‘where did you live five years ago?’

The regional council maps do so similarly for each of New Zealand’s 16 regions for the periods.

Percentage share of internal migration refers separately to the proportion of all internal arrivals to the selected territorial authority or regional council area from each other territorial authority area or regional council area, and the proportion of all leavers from the selected area to each other territorial authority or regional council area, as indicated at the 2006, 2013 and 2018 censuses.

Also shown in the accompanying information box to each map are the number and proportion of Usual Residents who were Stayers (people who were enumerated as residing in the same territorial authority area or region five years previously), the number and proportion living overseas five years previously, and a summary of net internal migration (internal arrivals minus internal departures). Because those living overseas at the time of the census cannot be enumerated (until they return), there are no equivalent data for overseas departures and thus net overseas migration cannot be shown.²

The number and proportion of people for whom address five years ago was not stated or unable to be defined or matched is also given. These numbers have been prorated across the ‘known’ Movers and Stayers under the methodological assumption that they will approximate those proportions—see below for more detail.

Key observations: The data indicate that the majority of both Internal Arrivals and Internal Departures concentrate around the territorial authority area or region from which they came or to which they went, irrespective of the census period. This concentration is indicative of the presence of ‘functional labour market areas’ (Papps and Newell 2002), where people with certain skills move away from or towards related jobs, and these are likely to be determined by local industry and land use.

However there are differences when the data are examined by age, with those over 65 years of age moving towards sun-belt and retirement hotspots, and those aged 15-24 years moving towards major cities (Brabyn and Jackson 2019, Jackson and Brabyn 2019, Brabyn et al 2019).

^{1. [There are three main population counts. The Census Night count pertains to all people counted in each area on Census Night. The Census Usually Resident Count (CURP) has reallocated people to their usual residence based on postcode, and removed overseas visitors. The Estimated Resident Population (ERP) count is released quarterly and includes adjustments for births, deaths and migration occurring since the previous census.]↩}
^{2. [Net overseas migration is, however, developed at ERP level and shown on the Net Internal and International Migration maps]↩}

'Mover-Stayer Methodology'

Census Usually Resident Population Counts (CURP) were originally sourced from Statistics New Zealand (2014, 2020) and are based on the Census question ‘where did you usually live five years ago?’ Because some people fail to provide this information on their census form, a methodological decision was made to prorate the data for those people according to the local (regional or territorial authority area) distribution for those whose address five years ago was stated (see caveat below).

Data for people who gave both their current and past address were categorised as either:

Stayers (people living in the same region or territorial authority area at both censuses—although they may have moved elsewhere within that area, and/or out of the area and back in, between the censuses);
Internal Arrivals (people living in the specified region or territorial authority area who lived elsewhere in New Zealand five years ago);
Internal Departures (people who lived in the specified region or territorial authority area five years ago, but now live elsewhere in New Zealand);
Overseas Arrivals (people who were living overseas five years ago);

Those who did not provide their current and/or previous address are recorded at the various censuses as either 'living elsewhere in NZ/not further defined', 'not elsewhere included/address five years ago not stated' or ‘unable to match’ (hereafter ‘Unmatched’. Unmatched data were prorated across ‘known’ migration as follows:

Stayers in each region or territorial authority area, Arrivals from each other region or territorial authority area, and Arrivals from Overseas were summed and their distribution calculated as a percentage. This percentage was then applied to the ‘unmatched’ number and the resulting number added to the number having stated their previous residence.

Leavers (Departures). The database is set up as a matrix, with area of usual residence 5 years ago juxtaposed against area of usual residence at each census. The resulting (prorated) Internal Arrival numbers to each territorial authority or regional council area simultaneously become Internal Leavers from those areas, based on their address 5 years ago.

Caveat: The methodological assumption that people who ‘lived elsewhere in New Zealand/not further defined’, ‘not elsewhere included/address five years ago not stated’ or ‘unmatched’ have the same mover-stayer distribution as those who did specify their previous address may be incorrect. We took this approach because it is preferable to calculating movements based on ‘known’ previous residence only, as these proportions differ substantially for each region and territorial authority area. The resulting data should thus be viewed as a best approximation of the situation and will differ slightly from the raw data that Statistics New Zealand publishes, and other analysts may generate.

Mover-Stayer Methodology (Summary)
1. TA/RC of usual residence (time t+5) by TA/RC of usual address five years ago (time t) are juxtaposed in a matrix
2. Stayers, Internal Arrivals, and Overseas Arrivals are summed and their % distribution calculated
3. Not Specified/Inadequately defined/New Zealand not further defined/unable to match are prorated
4. Prorated data are added to 'known' Stayers and Movers
5. Internal Arrivals (prorated) = the sum of Arrivals from all other TA/RC areas (CURP at t+5 years minus Stayers),
Internal Leavers (prorated) = Sum of Usual Residence at time t minus Stayers
6. Net Internal Migration at time t+5 = Net Internal Arrivals minus Net Internal Departures

Additional reading

Braybn L and NO Jackson (2019) A new look at population change and regional development in Aotearoa New Zealand. New Zealand Geographer 75: 116-129. DOI: 10.1111/nzg.12234

Braybn L, NO Jackson, G Stichbury, T McHardie (2019) Visualising and Communicating Population Diversity through Web Maps. New Zealand Population Review 45: 46–66

Jackson NO (2017) ‘Introduction and overview’ Policy Quarterly Supplement 13: 3-9.

Jackson NO and L Brabyn (2017) The mechanisms of subnational population growth and decline in New Zealand, 1976-2013’ Policy Quarterly Supplement 13: 22-36. http://igps.victoria.ac.nz/publications/PQ/2017/PQ-Vol-13-Supplementary-2017.pdf.

Papps KL and JO Newell (2002) Identifying Functional Labor Market Areas in New Zealand: A Reconnaissance Study Using Travel-to-Work Data. IZA Discussion Paper No. 443, Available at SSRN: https://ssrn.com/abstract=304439.

Preston K, D Maré, A Grimes, S Donovan (2018) Amenities and the attractiveness of New Zealand Cities. Motu Working Paper 18-14. Motu Economic and Public Policy Research.

Data Sources

Statistics New Zealand (2020) Customised Database, Area of Usual Residence (2018) and Usual Residence 5 Years Ago (2013) by Age Groups for the Census Usually Resident Population Count 2018.

Statistics New Zealand (2014) Customised Database, Area of Usual Residence (1996, 2001, 2006, 2013 and 2018) and Usual Residence 5 Years Ago (1991, 1996, 2008 and 2013) by Age Groups for the Census Usually Resident Population Count, 1996, 2001, 2006 and 2013.