Media Release: Data shows 42 decile 1 and 2 schools are some of the top performers in the country

Media Release
21 September, 2019

Low-decile schools are often viewed as being of lower quality by parents and are disproportionately categorised by ERO in the underperforming category.

However, findings from The New Zealand Initiative’s latest report, In Fairness to Our Schools: Better measures for better outcomes, suggests that many low-deciles schools are some of the top-performers in the country.

Following a comprehensive year-long econometric analysis, report author Joel Hernandez found 42 decile 1 and 2 schools outperformed 75% of every other secondary school in the country when evaluated on University Entrance.

The Initiative is calling for better and fairer measures of school quality in New Zealand. For too long, parents have relied on NCEA league tables and poor proxies such as decile to infer school quality.

In the absence of better information, decile drift and socioeconomic segregation have plagued New Zealand schools for decades.

One solution proposed in the report, is to utilise the world-leading database in Statistics New Zealand’s Integrated Data Infrastructure (IDI).

Using IDI data on nearly 400,000 students over 10 years the Initiative has developed a school performance tool that evaluated 480 secondary schools in the country; separating the contribution of each student’s family socioeconomic background from the contribution of each school.

If utilised by the Ministry of Education, the Initiative’s tool could generate annual reports for every secondary school in the country; providing fair, objective and data-driven information to principals, boards of trustees and the Education Review Office.

Crucially, the study shows that once adjusted for differences in family background, 80% of schools perform almost identically when evaluated on a wide range of NCEA metrics.

Joel Hernandez concludes, “New Zealand has an opportunity to improve the outcomes for every student in New Zealand using IDI data. It is time for the Ministry of Education to act. Left to the status quo, future students, particularly those from the most disadvantaged backgrounds, will pay the price.”

This report, alongside the corresponding technical report, Separating School and Family, are the first of many reports on school performance in New Zealand.


Dr Oliver Hartwich and Joel Hernandez are available for comment. To schedule an interview, please contact:

Simone White, Communications Officer
P: 04 494 9109 / 021 2937 250

Dr Oliver Hartwich, Executive Director
P: 021 0815 4973

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