Herald figures published today show that many lower decile schools increasingly cater to Maori and Pasifika - with high decile schools seeing a big jump in Pakeha and Asian enrolments.

The Ministry of Education points to changing demographics as one explanation for the trend, revealed by a Herald analysis of enrolment information.

However, principals say some families are avoiding local schools with low decile ratings, and the increasing divide between haves and have-nots must be addressed.

The changing ethnic make-up of New Zealand's schools has been characterised as "white flight".

"A healthy and harmonious multicultural society has its foundation in a schooling system," said Patrick Walsh, principal of Rotorua's John Paul College and executive member of the Secondary Principals' Association.

"The poverty faultline in New Zealand schools has created a huge divide from those schools who find it necessary to feed children breakfast, to those who boast world-class sporting and performing arts facilities."

Mr Walsh said the trend was often discussed by principals and sometime referred to as "white flight". However, he stressed the trend wasn't fuelled by racism - there was also "brown flight" to a much smaller extent. Families are simply moving in the belief higher decile schools provided better education.

#####Sharper rate of decline The number of Pakeha students at state and state-integrated schools dropped by nearly 55,000 between 1996 and last year.

Despite this, decile 8 upwards has seen a significant increase in Pakeha enrolments, while there has been a sharp decline at decile 1 to 5. Big jumps in Maori and Pasifika student numbers (37,858 and 25,870 respectively) have seen their enrolments at higher decile schools rise.

However, the rate of decline in Pakeha student population at lower deciles has been much sharper as compared to other ethnicities.

Asian numbers have more than doubled to nearly 76,000, with most of that growth going to higher decile schools.

Maori are now the majority ethnic group at low decile schools, with Pasifika approaching Pakeha as the second-biggest group.

For example, Pakeha now account for 26 per cent of decile 1-4 rolls, but in 1996 made up 45 per cent. Maori have gone from 35 per cent to 42 per cent, Pasifika 14 to 22 per cent.

The Herald analysis reflected reports from numerous low decile schools, Mr Walsh said.

#####Cherry picking One Auckland principal agreed to talk frankly if his school was unnamed as he did not want to help reinforce the trend. His roll is falling despite strong academic results.

Just over 60 per cent of the student population were Pakeha in 1996 and that has fallen to about 12 per cent. Changing demographics only partly explained the change.

"The bottom line is we should really have more Pakeha kids, because we don't reflect what's out there in the community at the moment.

"We are also losing some of the best Maori and Pasifika students ... they get cherry-picked [by other schools]."

Decile ratings were introduced in 1995 to promote equality, with low decile schools receiving more funding (decile ratings account for about 12 per cent of all operational funding).

Decile 1 schools are the 10 per cent of schools with the highest proportion of students from low socio-economic communities. Decile 10 schools are the 10 per cent with the lowest proportion of such students. Higher decile schools are often happy to take out-of-zone students, because Government funding is linked to student numbers.

The competition hurts schools with higher decile neighbours, such as Pakuranga's Edgewater College.

Out of zone Principal Allan Vester said in many cases the cost of housing and an ageing demographic in an area means there are fewer school-age residents.

"Schools which were allowed to expand their facilities in previous years of roll growth now find they have capacity that can no longer be filled by in-zone students. They then fill that capacity with students from outside their zone," said Mr Vester, also chairman of the NZ Secondary Principals' Council.

A NZ Council for Education Research survey of secondary schools, which included 1477 parents, found that 40 per cent of parents sent their children to a secondary school that was not their closest - usually to a higher decile school. The 2012 survey found almost all schools with enrolment zones took students from outside their zone.

For some schools, particularly in South Auckland, a lack of Pakeha students is not new.

Mangere College has only 2 Pakeha students out of around 800. The decile 1 school has about 10 Asian students, 618 Pasifika and 154 Maori.

Principal John Heyes said such numbers had been common since the early 1980s, and reflected the demographics of his school's catchment area. Students from the more affluent Mangere Bridge suburb had always crossed the bridge to schools in Onehunga and beyond.

Dr Graham Stoop, the ministry's head of student achievement, said the social and ethnic mix of communities changed over time, like most other Western societies.

He said care needed to be taken when tracking student movements, as decile ratings had changed a number of times since the 1990s. It was not uncommon for students to attend a school whose rating has changed several times.

The ministry is expected to tell schools this week whether their decile has changed, after a post-Census recalculation exercise.

#####Parent choice There have been recent efforts to reduce competition between schools, including the Government's flagship Investing in Educational Success programme. It aims to identify the best principals and teachers and pay them more to spend time in other local schools or provide an example within their own.

However, National has also signalled a commitment to parent choice. It is a key philosophy behind the expansion of charter or "partnership" schools, a publicly-funded but privately-run model targeting students who have not done well in mainstream schooling.

Alwyn Poole, who runs one of the first partnership schools and will soon open another, Middle School West Auckland, said he had been stunned after examining the achievement rates of some low decile state schools.

"I don't think you can belittle parents in terms of them being nervous about a school's results or reputation, and wanting to make sure they have really good options for their children."