In contrast, only 39 per cent of those in care are European, compared with 71 per cent of the under-20 population. Pacific children make up 11 per cent of the young population but only 6 per cent of those in state care.
Dr Cram said other countries that had been colonised by immigrant groups showed similar patterns.
"Around the world, indigenous children are over-represented in child welfare systems for many reasons: systemic racism, the application of white, middle-class standards and values to [indigenous] communities, and inter-generational fragmentation of the family and community structure," she said, quoting an Australian study.
"The high proportion of these children whose families live in deprivation suggests that this over-representation can be substantially accounted for by structural risk factors such as poor housing and poverty."
In New Zealand, the Social Development Ministry says one-third of Maori children and a quarter of Pacific children, but only one-sixth of European children, lived in homes with incomes below 60 per cent of the median after adjusting for housing costs between 2007 and 2010. It says the main factor pushing up the Maori figure was a high number of sole parents. Almost half (43 per cent) of sole parents on the domestic purposes benefit in the period were Maori.
Dr Cram, who comes from the East Coast iwi of Ngati Pahauwera, found that 54 per cent of Maori, but only 24 per cent of non-Maori, lived in the most deprived 30 per cent of areas in the country at the 2006 Census. She said Otago University research showed that this was partly due to ethnic discrimination.
"If you take a cohort of Maori and a cohort of non-Maori who are the same in age, gender and education levels, the Maori will end up in lower-status jobs," she said. "Structurally, it's discrimination. You could say personally, in terms of whanau, it's because the knowledge of how to move through education into employment is not as embedded in whanau."
She is evaluating a programme run by Auckland tertiary institutions, Maori Into Tertiary Education (MITE), which helps Maori students to get from school into tertiary education and then into internships in Auckland companies.
Her report praises other programmes working from a Maori value base and she believes the new Whanau Ora policy, which aims to give Maori agencies more flexibility to help families with all areas of their lives, also offers hope.
"But it shouldn't let mainstream providers off the hook," she said. "There are still big challenges for government agencies in becoming more responsive to Maori and to working with whanau."
ON THE WEB
www.nzfamilies.org.nz
www.mite.org.nz