Session 2c, Social Surveys

This session will be held in the Erskine Building, Room 031

14:15 — 14:35

Nothing to worry about: problems in the disaggregation of expenditure statistics

Geoffrey Jones
Massey University

Stephen Haslett
Massey University

Jamas Enright
Statistics New Zealand

This project, funded by the StatResearch programme of Statistics New Zealand through the Official Statistics Research and Data Archive Programme (OSRDAC), investigated the use of small-area estimation techniques for breaking down national expenditure statistics into different ethnic groups, with a particular focus on Maori, and into different expenditure groups. Data from the 2001 New Zealand Census were used to add strength to the direct estimates available from the 2001 Household Expenditure Survey via a unit-level regression model. While the method worked successfully for Total Expenditure, the attempt to extend the methodology to estimation of the finer CPI expenditure categories met with some interesting practical and methodological problems.

14:35 — 14:55

The Post-Enumeration Survey-Features of the Estimation Methodology.

Judith Archibald
Statistics New Zealand

Counting more than four million people throughout New Zealand is a major undertaking, and inevitably some people will be missed or counted more than once by the census. Many countries conduct surveys to estimate the populations not enumerated by their censuses. The 2006 Post-enumeration Survey (PES) was the third to be undertaken in New Zealand since the inaugural PES in 1996. The main objective of the 2006 PES was to gauge the level of national coverage (undercount and overcount) in the 2006 Census.

This paper will describe the statistical rationale behind the PES and the principles of the estimation methodology. It will also discuss some methodological extensions to deal with the practicalities of the Census environment.

14:55 — 15:15

Modelling Social Change: The parameterisation of log-linear models to measure inter-ethnic cohabitation patterns in New Zealand.

Lyndon Walker
University of Auckland

This paper discusses the application of log-linear modelling techniques to Census data in order to examine cohabitation patterns in New Zealand from 1981 to 2001. The main focus of the study is ethnic homogamy (couples where each partner has the same ethnicity) amongst couples who live together and how it has changed over this time period. A quasi-independence (or diagonal dominance) model is applied to each period in order to see the relative degree of homogamy across different ethnic groups. This model is then reparameterised to incorporate a time factor so that the changes in each group can be measured across the five Census periods. An alternative parameterisation known as the "crossing parameter model" is then applied to the data to test whether there has been a change in the degree to which people will cross ethnic boundaries in their relationships. In particular this parameterisation aims to test whether there is a difference in the cohabitation choices of people who have indicated more than one ethnicity in their Census form.

Presentation Program