Page 279 - Invited Paper Session (IPS) - Volume 1

IPS153 Christine B. et al.
(Statistics NZ, 2014a). The ERP adjusts for net undercount in the census, as
measured by a coverage survey (Statistics NZ, 2014b). Population change from
census day applies a cohort component method using high quality Birth and
Death registrations, and measures of external migration.
New Zealand is fortunate in having excellent information sources on
external migration. We are an island country with a record of border crossings
that includes almost all travel journeys into and out of the country. Measures
of external migration have until recently used passengers’ stated intentions on
arrival or departure to differentiate short-term travellers from long-term
movements (migrants). In practice, intentions do not always correspond to
actual length of stay in New Zealand or overseas.
Stats NZ committed to exploring the use of administrative data for the
census in its Census Transformation Strategy (Statistics NZ, 2012). The strategy
consists of two parallel strands. The first is a short to medium term focus on
modernising the current full enumeration census, with the first
implementation in the 2018 Census of Population and Dwellings. The second
strand is investigating the feasibility of a census largely based on
administrative data in the long-term. The two strands are inter-dependent and
the 2018 Census includes a goal to increase the use of administrative data. The
main use of administrative data in 2018 was to construct an address frame
from administrative sources, which has developed some of the organisational
infrastructure required for long-term change. The 2018 Census strategy also
included use of alternative sources to improve data quality in the context of
missing data for census questions, based on the findings of the longer-term
administrative data research. The value of this joint strategy has become clear
in the light of lower than anticipated response rates in 2018, which has
considerably extended the role that administrative data now plays in the 2018
Census.

2. Census Transformation programme
Stats NZ’s Census Transformation programme is exploring the feasibility
of a census based largely on administrative data, and supported by sample
surveys. Bycroft (2015) describes the administrative data landscape in New
Zealand, and progress producing an administrative resident population to that
point. Stats NZ reports to government periodically, outlining progress and
seeking decisions on future direction. In a 2015 Cabinet paper government
agreed that Stats NZ actively work towards a future census based primarily on
government administrative data, supported by redevelopment of its
household surveys. The linked administrative data sources available in Stats
NZ’s Integrated Data Infrastructure (IDI) have been the basis for this research.
The IDI provides safe access to anonymised linked microdata for research and
statistics in the public interest. The basic structure of the IDI consists of a

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