Rachael Meyer recently asked one of her twin 16-year-old daughters if she thought attending private school would have made her a different person.
It was a pertinent question because, while Meyer and her husband were giving the twins a state education at Botany Downs Secondary College, they had already paid approximately $100,000 to put their eldest child, Cameron, through the private St Kentigern College.
It was a question that parents - particularly those with an income somewhere between "reasonably comfortable" and "quite a bit" - have long asked themselves and will continue to ask until someone can provide a firm answer on whether paying very large sums of money to send their children to private school is better than paying effectively nothing to send them to state schools.
Given the large number of possible answers, Meyer was a little surprised by her daughter's response: "She said to me, 'I probably wouldn't have been as mindful of other cultures and people that don't have as much as we have'."
It was an answer that got to the heart of the issue behind the question. What do we mean by "better"? It's easy to judge schools by their academic results but schools are responsible for not just teaching children, but for myriad other things: making sure students are safe and happy; giving them rich experiences and an understanding of the world; helping them learn how to interact with others; helping turn them into fully formed adults, whatever that means.
Meyer says she faced a lot of pressure to send her daughters to private school, and she did consider it. She even offered them the opportunity, although it came with some financial realities, such as not being able to move to a bigger or better house, there would be no overseas trips and parental expectations would be higher.
She says she didn't feel as though the twins needed private school, while her son did. "They were not shy, they're already out there, they'd put their hand up to answer a question, no problem. Cam would always sit in the background."
For Meyer, it was about matching her children to the education style needed. She felt that Cameron, a gifted sportsman, would be less academically supported in the public system, and that the streaming and boys-only classes of St Kents would be good for him. She also believed that the quality of teaching would be better.
Statistics can tell us some things about what private school can deliver but it's still an open question as to whether it represents value for money.
Education is the outsourcing of the realisation of our children's potential. We hand them over and say to the school, "Help turn this child into the adult I would have turned her into if I had the time, skills and resources you do."
You can assess charts comparing schools' academic achievements, you can read reports and you can have students show you around a school, to get a feel for what the place is like from the people who use it, as some principals like to suggest.
You can see what sort of children go there and whether they're the sort of people you want your child to build lifelong connections with. But there are so many variables left unaccounted for.
How similar are a school's current students to your own and how does the school deal with the differences? What is the impact of individual teachers? What is achievement anyway?
For parents, there are few more important decisions and few that can be so easily second-guessed. The variables are enormous. You just want to have confidence you're doing the right thing. The thing is, our conceptions of "the right thing" are all different.
"Whatever they do [after finishing school], I don't care," Meyer says of her children. "Cam's gone into building. People said to me, 'Is that not a bit of a dropout? You spent all that money on schooling.' And it's like, 'no not at all, because you can take building to wherever you want it to go'."
Dividing schools into two categories, state and private, requires making some broad generalisations. Every private school principal will tell you what makes their school different not just from state schools but from every other private school, and those differences will sometimes be quite marked. Parents and teachers with views on "private schools" are often referring only to the school their children are at.
That doesn't stop people having a view of the value or otherwise of private school. One common opinion has to do with smaller class sizes. Research suggests that class size doesn't make a difference to educational outcomes - although many teachers would tell you differently - and there is doubt as to whether classes are consistently smaller in the private sector anyway.
Higher funding for lower decile state schools in particular allows them to boost teacher numbers. At Mangere Central, a state primary school, principal Maria Heron says she doesn't like class sizes to go higher than 25 and next year they will have classes as small as 15 or 16, for younger students.
Both parents and educators frequently mention the quality of facilities at private schools. "Yes, they do often have better facilities," says Allan Vester, principal of state school Edgewater College. "Some state schools with significant fee-paying students won't be far behind. Used well, the better facilities can help. However, it's my view that what makes the real difference is the teacher.
"A fantastic teacher in a classroom with a dirt floor and a pointed stick will still be much more effective than a poor teacher with all the technology possible. And as far as I can tell, the state system continues to get its share of those fantastic teachers."
Meyer says while she once thought that private schools had better teachers than state schools, her view has changed since her daughters started high school: "I think teaching is a passion. I don't think people do that because they want to earn big money. I get that now.
"It's all about the individual teacher. We came across some shitty teachers at St Kents and we've come across that in public school too, but I think less so, to be honest. I think there's probably been more passion with the public teachers than the private."
Private schools don't pay teachers as much extra as you might think - one teacher who has taught in both state and private schools put the difference at about 5 per cent - so the incentive for the best teachers to cross over is not always huge.
Jess Thomson, now 21, attended two private schools, starting at Corran School then moving to St Kentigern College. She says she felt a lack of support from many of her teachers at Corran. But one inspiring teacher there, with whom she's still friends, helped her get through.
"It can be a really vulnerable time when you're at school," Thomson says. "You're growing up and it's almost not about the academic side of things. It's a very vulnerable time. Aimie was so important to me. I just clicked with her and I think that's so important for any student to have just one teacher that pushes you a bit or tells you you're good in a certain area. I think things would have been quite different had I not had her."
Jess' mum, Suzie Thomson, says she sent her daughter to Corran because she felt the small size of the school would be better. However, looking back, she says if she had known how bad Jess would feel there, she would never have sent her there.
"We were just lucky to have someone like Aimie because she tapped into what Jess was good at and recognised her as a person. Jess said she was the first person that acknowledged [her] and spoke to her like she was an intelligent being. I think a teacher anywhere can make that change, whether in a state school or private school. I think if you have someone who acknowledges you as a person and you have worth, that you will thrive wherever."
Obviously, finding a teacher like that is a crapshoot. Even if you heard about a school with a preponderance of such teachers and it was enough to convince you to send your child to that school, your child might not respond to them, or might never even be in their classes.
About 85 per cent of all students in New Zealand attend state schools. Of the remaining 15 per cent, 11.5 per cent go to state integrated schools - funded by the state, but able to charge for facilities.
Many prominent integrated schools are Catholic - Baradene, St Peter's, Sacred Heart - and they charge students anywhere from a few hundred dollars a year to almost $5000 a year.
That leaves about 3.5 per cent of all students in New Zealand at private schools. In Auckland, the figure is around 5.5 per cent. With small fluctuations, these numbers have stayed reasonably consistent since the turn of the century and they are low by international standards. In Australia, around 40 per cent of all students attend private schools.
Private schools can set their own fees and also decide what else they want to charge for. For instance, In addition to its $19,625 tuition fee, St Kentigern College charges a non-refundable application fee of $300, a non-refundable enrolment acceptance fee of $900, a compulsory association fee of $575, a compulsory notebook computer purchase of approximately $2000, a software licence fee of $250, estimated uniform costs of $1200, a publications fee of $220, various charges for "sports trips and activities" and various "other curriculum-related charges" including, but not limited to, field trips, workbooks, camps and education outside the classroom.
The variable nature of such costs and the way different schools charge for them means it's difficult to put a definite figure on a private education. But for the top rung of schools, $20,000 per year is a conservative figure (at King's College, fees for year 12 and 13 students are $24,093). For parents wanting to put two children through seven years of schooling, from years 7-13, that's a starting figure of $280,000.
Erin and Stephen Mills, of St Heliers, are delighted with their children's private educations. Their daughter went to St Cuthbert's and is now at law school, their oldest son is entering year 12 at King's College and their youngest son is going into year 6 at King's School.
"We think they'll leave being ambitious and driven, with goals," Erin Mills says. "It's competitive - I think it's pretty important to have that competitiveness because that's reality. They graduate as grounded young adults with strong values and service towards the community. We also like the sense of tradition. We feel it's the complete package."
She says they're impressed also by the opportunities beyond straight academics, like public speaking, languages and musical instrument lessons from an early age. And the competition.
"I think today it's all getting a bit lost, the idea that there are no winners," she says. "My husband and I think it's quite confusing for a young adult to be in that situation ... These schools are competitive and they talk openly about competition. If you win at things or if you do well at things, you're commended for it and if you're not doing so well, they're good at that as well."
Edgewater College's Vester says, "While a school can make a positive difference, most research points to about 70 per cent of final educational achievement being predicted by factors outside the school. Parental income and the educational level of the mother are two factors that are the strongest predictors of educational achievement."
Research from the OECD's programme for international student assessment (PISA) suggests that private schools perform better academically than public schools as a whole, but not better than public schools with student populations from similar socio-economic backgrounds.
New Zealand academic results show that, on average, private schools outperform public schools of the same decile level. Eighty-seven per cent of leavers from decile 10 private schools achieved the equivalent of NCEA level 3 or above in 2014, compared with 70 per cent from decile 10 public schools.
Trying to get your child into a high-performing, high-decile state school can be even more expensive than paying to send your children to private school. A Herald article last year showed that where the Auckland Grammar School zone splits a street in two, in-zone houses cost up to $272,000 more than comparable houses across the road. Over the life of a 20-year mortgage, with interest, the total extra cost of buying that in-zone house could be close to $500,000.
Anyway, nobody advocates choosing a school based solely on academic results.
Diocesan School for Girls principal Heather McRae says: "We always get students to show parents around because students are so honest about their school. They're able to articulate really clearly what their experience is.
"Visit a school, have a look and get a feel for the people in the place. In the end, the facilities do make a difference but the people do too. It's the relationships everyone will have with each other and with their children that will make a difference to their lives."
McRae says that in the state sector, "you would take all your subjects and there would be the assumption you would come out as a great young person", while her school emphasises a series of programmes about developing character attributes, including ethics, leadership and spiritual development. She says that state schools give such values-based education little support and few resources.
Vester says that while private schools have more money and therefore an often greater ability to provide facilities and opportunities for students, there is no evidence that private school leavers dominate further education or employment.
Educational commentator Stuart Middleton, of Manukau Institute of Technology says that the work done in state and private school classrooms can be quite similar but what's done outside the classroom is significantly different.
In the end, is that a difference that is worth the extra expense?
"It's the two words, 'better education' that are difficult," Middleton says. "Pretty well every school in the country will give someone a good education. But, 'better', I think, is a code for something else."
$24,093 (years 12-13)
St Cuthbert's College
$21,224 (years 7-13)
Diocesan School for Girls
$20,480 (years 7-13)
$20,380 (years 11-13)
St Kentigern College
$19,625 (years 7-13)
ACG Parnell College
$19,380 (years 11-13)
$18,500 (years 12, 13)
Pinehurst Senior College
$16,134 (years 9-13)
$4628.80 (year 13)
Sacred Heart College
$3768 (years 9-13)
St Peter's College
$3164 (years 9-13)
$2366 (years 9-13)
McAuley High School
$792 (years 9-13)
Worth the extra expense
Andrew Keighley, father of Amanda (13) and Josh (14), who are at St Kentigern College, says the school delivers value for its annual fees of almost $20,000 per student.
"It doesn't mean your children are going to be academically brilliant," he says. "It just means you're going to give them opportunities. I think that's the key: the opportunities of so many activities beyond the core curriculum. Not everyone's going to be a rock star but if there's a particular thing that interests them, if the school can accommodate that, then I think that's great."
Keighley says he's been impressed by the engagement of the teachers at St Kentigern, and by the school's level of accountability. Parents are encouraged to get in touch by email and personalised responses usually arrive within 24 hours. Parents love it, he says: "I'm yet to come across people who say it was a bad investment or they would have been better to spend money on other things."
Five things you could spend the money on
1: Put $20,000 a year in Kiwisaver for them.
According to sorted.org.nz, if you deposit a lump sum of $100,000 in Kiwisaver at high school leaving age, that could turn into $445,695, adjusted for inflation, by their retirement age. That's even before your children have made any of their own contributions over the subsequent 48 years.
2: Take the family on a grand overseas trip every year your child is at high school.
You could try a new continent each time, although, with only five years, you'll have to skip a couple. For under $10,000, you could take the 11-day Intrepid Travel Borneo Family Adventure. "Learn how orphaned orangutans are rehabilitated back into the wild, swim among colourful fish and spot wildlife in Borneo's steamy jungles. Along the way, make friends with local villagers, try delicious cuisine and enjoy plenty of time to kick back and relax."
3: Give your child the gift of intensive sports training.
One-on-one tennis lessons can be had for $60 an hour. Two of those every week for a year will cost a total of $6240. Or, if you really believe your little one could go the full Federer, you could get lessons every week day for a year for $15,600.
4: Make up for any deficiencies in academic talent.
Private tutoring varies wildly but many advertise their services for around $40 an hour. Five hours of tutoring a week across the 40 weeks of the school year will set you back $8000.
5: If you've got an aspiring dancer:
The best training ground is not school but The Palace, the studio of New Zealand's world-beating dance queen, Parris Goebel. Two private lessons a week at The Palace each week of the school year will cost about $8000.