Despite New Zealand schools receiving lower funding than many other OECD countries, students here are among the world's top achievers, according to a new report.

An OECD Programme for International Student Assessment (Pisa) report, released today, looked at the correlation between national wealth and student achievement, and found the amount spent on education was less important than how resources were used in high-income economies.

"The strongest performers in the Pisa are not the wealthiest, nor do they allocate more money to education," it said.

"A country's/economy's cumulative expenditure on education is the total dollar amount spent on educating a student from the age of six to the age of 15. After a threshold of about US$35,000 ($41,600) per student, that expenditure is unrelated to performance."


Norway, Switzerland and the United States all spent more than US$100,000 per student, but showed similar levels of performance as Hungary, Estonia and Poland - countries that spent less than half that amount per student.

New Zealand also received a special mention, with the report noting that it was a "top performer" in Pisa, but spent a lower-than-average amount per student.

However, while the education sector has welcomed New Zealand's high achievement rates, there is concern the Government might use another finding in the report to boost its argument for class sizes.

The report showed the strongest performers among the high-income countries tended to invest more in teachers and have larger classes.

"At the country level, Pisa finds that the size of the class is unrelated to the school system's overall performance; in other words, high performing countries tend to prioritise investment in teachers over smaller classes," it said.

Education sector unions have consistently pushed to bring down student-teacher ratios, and NZEI president Ian Leckie raised concerns that today's report may be seen as an excuse to justify money-saving measures.

"The report should not be used as an opportunity to adopt Treasury's misguided advice about increasing class size in order to free up money in education," he said.

"We should step up investment in the areas that we know return the best investment ... supporting quality teaching and keeping class sizes, especially for new entrants, as low as we can so that teachers can provide the individual feedback to children that is important for learning."


Labour education spokeswoman Nanaia Mahuta also voiced concern about class sizes, saying increasing class sizes would only compound the pressure on teachers.

High expectations for all students was another common factor across successful Pisa countries, the report said.

"Schools and teachers in these systems do not allow struggling students to fail, they do not make them repeat a grade, they do not transfer them to other schools, nor do they group students into different classes based on ability," it said.

Mr Leckie said National Standards and charter schools risked taking New Zealand down the road to separating students based on performance.

"They encourage the labelling of children and can lead to segregated learning environments both in the classroom and within the wider community," he said.

"None of that equates to improved student achievement or teacher quality."


In a statement welcoming the report today, Education Minister Hekia Parata said it was clear a number of factors influenced achievement, and noted the class-size finding as "interesting".

Ms Parata said the Government already recognised that high quality teaching was "extremely important".

"Our Government's key objective is to ensure every child has the opportunity to succeed. Over the next three years we want to significantly raise achievement for all students, especially those groups of students who have historically under-performed," she said.

Pisa reports are compiled every three years.