Cross classification of the New Zealand population by ethnicity and deprivation: trends from 1996 to 2006.

OBJECTIVES: To describe trends in the distribution of New Zealand's major ethnic groups by small area deprivation and trends in the ethnic composition of each deprivation category.
METHODS: Data sources were the 1996, 2001 and 2006 New Zealand Census of Population and Dwellings. Ethnicity (Māori, Pacific, Asian or European/Other) was defined using total response output. Each person was assigned a deprivation score by geocoding their usual residence (as recorded in the census) to meshblock level. For each time period (1996, 2001 and 2006) the deprivation score for each meshblock was calculated by principal components analysis from nine socio-economic variables included in the corresponding census (the New Zealand Index of Deprivation).
RESULTS: Throughout the observation period, Māori and Pacific ethnic groups were over-represented at the more deprived and under-represented at the less deprived end of the deprivation spectrum. The European ethnic group displayed less-marked skewing, and in the opposite direction, while the Asian ethnic group showed close to the expected uniform distribution. Neither the deprivation distribution of any ethnic group, nor the ethnic composition of any deprivation decile, showed any statistically significant change over the 10-year observation period.
CONCLUSIONS: Monitoring trends in the relative deprivation distributions of the ethnic groups helps assess progress towards social justice. Similarly, monitoring trends in the ethnic compositions of the different deprivation deciles is important in the formulation of social policy. Little change was found in either of these distributions over the relatively short observation period.