This research note takes a closer look at school effectiveness across state, state-integrated, and private schools, otherwise defined as school authority (or type) using the Initiative's school performance tool.

In a New Zealand first, we estimate each school’s contribution to student achievement across the three school authorities after separating out the contribution of the family socioeconomic background using data from Statistics New Zealand’s Integrated Data Infrastructure (IDI).

Part One of our analysis compares the average estimated effects of attending different school authorities and the increase or decrease in the likelihood of attaining University Entrance (UE).

Part Two looks at individual school performance across each school authority, particularly the percentage of state, state-integrated and private schools in the top 25% (high-performing), middle 50% (average-performing), and bottom 25% (low-performing) of all secondary schools in the country.

Part Three examines the socioeconomic factors predicting which school authority a student might attend.

Part Four compares these findings with the OECD’s Programme for International Assessment (PISA) results on private versus state schooling. The report concludes with our policy recommendations.

The Appendix contains a brief description of the modelling behind the analysis. Our previous technical report, Separating School and Family: Evaluating the effects of school and family background on student performance (2019), further explains the school performance tool.

Part One: Average UE attainment across school authorities

• For the first time in New Zealand, this report shows state-integrated schools marginally outperform private schools on average. The report also reveals both state-integrated and private schools significantly outperform state schools on average.
• In practice, we estimate that the average student would increase their chance of attaining UE from 30.5% to 38.8% when attending a state-integrated school over a state school compared to 30.5% to 37.4% when attending a private school over a state school.

Part Two: Individual school performance in UE attainment across school authorities

• On individual school performance, we show students in private schools are more likely to attend a high-performing (top 25%) school compared to both state-integrated and state schools;
• 66.7% of private schools fall in the high-performing category compared to 45.2% of state-integrated schools or 15.5% of state schools.
• Conversely, there is a marginally greater chance of attending a low-performing (bottom 25%) private school compared to a state-integrated school;
• 8.3% of private schools fall in the low-performing category compared to 6.5% of state-integrated schools or 31.8% of state schools.

Part Three: Predictors of attending school authorities

• Parents’ educational attainment is one of the strongest predictors of attending a private or state-integrated school once our school performance tool also separates the effects of parents’ income among other major socioeconomic factors.
• After adjusting for parents’ income and education, Pasifika students are more likely to attend state-integrated schools compared to Asian students who are more likely to attend private schools or Māori students who are more likely to attend state schools.

Part Four: PISA results across school authorities

• The OECD found students attending private schools in New Zealand significantly outperform students in state schools. But after accounting for student and family background characteristics, this difference disappears almost completely.

This report reveals that New Zealand’s state-integrated schools are doing much better than previously thought.

Since State-integrated schools were incorporated into the state education system under the Private Schools Conditional Integration Act 1975 private schools have generally been viewed as better academic performers. However, this report shows for the first time that students on average have a greater chance of attaining UE at a state-integrated school than at a private school (after separating out the contribution of family socioeconomic background).

This report also raises concerns about the quality of public schools in New Zealand. While 15.5% of state schools perform in the top 25%, we show 31.8% of state schools perform in the bottom 25% even after adjusting for the different communities they serve. In comparison, only 6.5% and 8.3% of state-integrated and private schools fall in the bottom 25%, respectively. In absolute terms, New Zealand’s 330 state schools include 51 high-performers; 93 state-integrated schools include 42 high-performers; and 36 private schools include 24 high-performers. 

Of course, UE attainment is not the only important school outcome. Yet if greater educational opportunity is the goal, these results are a serious cause for concern. To improve our education system, the Ministry of Education must learn which schools are bucking the trend and overcoming socioeconomic barriers. This report shows just that.