Page 278 - Invited Paper Session (IPS) - Volume 1

IPS153 Christine B. et al.

Linked administrative sources for the New
Zealand census and population statistics
Christine Bycroft, Pubudu Senanayake
Stats NZ Christchurch, New Zealand

Abstract
Statistics NZ is beginning to see the benefits of a programme of research into
greater use of administrative data for the population census and the wider
population statistics system. The research effort has been driven by a need to
modernise and reduce costs of the current full-enumeration census model,
and the opportunities afforded by a rich and growing set of integrated
administrative data. Development of new statistical models is integral to
maximising the use of administrative sources. Included in this data mix are
travel journey data for almost all border crossings – a rare advantage afforded
by being an island country. A new measure of external migration has been
developed based on actual time spent in NZ, rather than the previous
approach that used intentions stated on arrival and departure cards. While NZ
does not have an administrative population register, or any mandatory
requirement to register an address with authorities, we have developed a
statistical admin resident population based on a ‘signs of life’ approach. This
work has proved to be a significant advantage given an unanticipated level of
non-response in the most recent full enumeration census in 2018.

Keywords
population estimation; linked administrative data; external migration; census

1. Introduction
Administrative data have always been part of the production of Stats NZ’s
official population statistics, however, the ways in which administrative data
are being used is changing. These changes are taking advantage of
opportunities afforded by the integration of administrative sources which
were formerly only available separately, and the development of new statistical
methodologies that are needed to take full advantage of the linked data. As
well as these opportunities, change has been driven by concerns about cost
pressures and the sustainability of the current full enumeration census.
Population statistics in New Zealand are based on a five-yearly full field
enumeration census. The census data are released in their own right and
provide a rich array of social and economic information for small sub-groups
and small geographies. A separate official Estimated Resident Population (ERP)
series is the best measure of population living in New Zealand at a given time

267 | I S I W S C 2 0 1 9