New Zealand Socioeconomic Index

The New Zealand socioeconomic index (NZSEI) attempts to derive an occupation-based measure of socioeconomic status.


The framework used for NZSEI is the ‘returns to human capital’ model, which was first developed for the International Socioeconomic Index (ISEI). This model posits that there is a relationship between cultural capital and material rewards, and that this relationship is mediated by occupation. More simply, the ‘returns to human capital’ model views occupation as the means by which one’s education is converted into income. Thus, differences in occupation are likely to represent differences in life chances and opportunity, and on this basis, occupation can be used to stratify individuals according to socioeconomic status.

New Zealand socioeconomic index 2006

We have developed the NZSEI-06, an occupation-based measure of socio-economic status derived using data from the 2006 New Zealand Census. The NZSEI-06 can be used both as a continuous scale (from 10, low SES, to 90, high SES) and as a categorical grouping of occupations, and is applicable to both full- and part-time workers and the self-employed. Initial assessments of the scale suggest that it classifies occupations similarly to its predecessor (the NZSEI-96) and also similarly to an Australian occupation-based SES scale, the AUSEI-06. The NZSEI-06 also validates well against a number of health and socio-economic correlates for both sexes and also for four major ethnic groups: European and Other (including New Zealander), Māori, Pacific, and Asian. As a measure of individual SES, the NZSEI-06 requires only occupational data for its classification, and so can be readily applied to administrative datasets and social surveys. Moreover, ‘imputed’ NZSEI-06 scores appear suitable for the classification of those outside of the workforce. Thus, the NZSEI-06 is likely to be a useful addition to the toolbox of researchers wishing to assess and understand the impact of SES on a range of outcomes.

The NZSEI-06 report describes the construction and initial assessment of the New Zealand socio-economic index 2006 (NZSEI-06), which is an update of the New Zealand socio-economic index (NZSEI) using 2006 Census data. Both NZSEI-06 socioeconomic scores (ranging from 10–90) and NZSEI-06 socio-economic groups (a six-group classification, NZSEI-06 quartiles and NZSEI-06 deciles) are described and evaluated.

New Zealand socioeconomic index 2013

The forerunner of NZSEI was the widely-used Elley-Irving scale, which assigned occupations to one of six socioeconomic status groups based on equal weighting of education level and income associated with each occupation. NZSEI represents an attempt to derive an occupation-based measure of socioeconomic status for New Zealand that can be used as both a continuous and a group measure, and is grounded in a conceptual model that differs slightly from the Elley-Irving framework.

The original version, NZSEI-91, was derived using 1991 Census data. Since then there have similarly been NZSEI-96, NZSEI-06, and the most recent NZSEI-13. These two most recent versions have been developed through summer studentships within COMPASS. Reports on these are available below, along with the derivation of scores for NZSEI-13.