Abuse in care inquiry

The problem

The Royal Commission sought to understand the long-term impact of children and young people placed in State residential care between 1950 and 1999, specifically their likelihood of later incarceration. This analysis was designed to meet the requirements of the Royal Commission's Abuse in Care Inquiry. Our analysis drew on the Stats NZ Integrated Data Infrastructure (IDI) to identify incarceration rates among those in State care and comparing them to a matched cohort.

Our approach

A data linkage methodology was used, combining historical records from Oranga Tamariki (added to the IDI with the support of the Royal Commission and Stats NZ) with sentencing data from the Ministry of Justice and Department of Corrections, using the IDI. Key steps are outlined below:

Dataset creation: A list of over 30,000 people who had been in State care between 1950–1999 was compiled.
Identity matching: Individuals were matched to IDI records using Ministry of Health and Corrections data.
Custodial sentence search: Incarceration records were identified within the IDI.
Matched cohort construction: A comparison group was built to match on age, sex/gender, and ethnicity.
Conservative estimates: Assumptions were made that unmatched individuals had not been incarcerated, likely underestimating the true rates.

Impacts

The evaluation identified the following key findings:

One in five to one in three people who had been in State care later received a custodial sentence.
In contrast, only 1 in 13 in the matched cohort (not in care) were incarcerated.
Those who had been in care were 5 to 9 times more likely to be incarcerated than their matched peers.
For Māori, the likelihood was 4 to 7 times higher; for non-Māori, 15 to 24 times higher.
Māori were heavily overrepresented in the care cohort—nearly 50%, compared to 13% of the general population at the time.

The findings confirm a strong association between State care and later imprisonment, though it is important to note that causation cannot be inferred from the data alone. The disparities for Māori are particularly concerning, reflecting broader systemic patterns of institutional racism and intergenerational harm. Results further suggest that being placed in State care significantly increases the risk of incarceration, even when controlling for age, sex, and ethnicity.

Further research is needed to better understand why these links exist and how they might be prevented. Policies and services should prioritise support for care-experienced individuals, with a particular focus on Māori, who are disproportionately impacted. Ongoing improvements to data governance are also essential, especially in relation to Māori data sovereignty. Finally, enhanced early intervention and trauma-informed care approaches may play a critical role in disrupting the care-to-custody pathway.