But this isn't about public vs. private. I know from experience that private schools are *full* of helicopter parents and sheltered little snowflakes. While private schools have higher test results, that is entirely from the kids being richer and having the best money can buy for them. When the same kids are put in public and private, their test scores are basically equal.
In Australia: no. It's demographics. Peers.
We've a website called
MySchools which lets you look up and compare schools. There are three key numbers we can look at,
NAPLAN results. These are nationally-standardised tests. There are some issues with them, not everyone agrees with them - but they're what we have for comparing academic performance across schools.
Per student spending - that's from both public and private sources, the numbers are all there
ICSEA distribution. That's the index of community and socioeconomic advantage, which is a measure of how well-off and well-educated the kids' parents are. They give a raw number to it which nobody understands, but also quartiles. The mythical perfectly-representative school would be 25-25-25-25, equal proportions from each quartile. A school in a poor area might be 65-20-10-5, a school in a well-off area 5-10-20-65. Let's just consider the top and bottom quartiles since the others tend to be in proportion.
When you look over enough schools, you find that the spending makes not much difference to the outcomes - but ICSEA is huge. Consider:
Kew Primary has 2% bottom quartile and 63% top. It gets $10,610 per student. As for results, grammar in year 5 is 505, and numeracy 518.
Broadmeadows Primary, on the other hand, has ICSEA 58/5, spending $14,533 per student, and year 5 grammar is 474 and numeracy 472. More money than Kew, but worse results. Why? Peers.
When you're paying for a private school, what you're really paying for is their peers - high ICSEA students. It's a way to ensure that your kids spend time with kids whose families are well-off and well-educated. Obviously if you want your kid to be a High Court judge some day then you're also paying for the networking etc - there's a pic floating around in Australia right now showing the Commonwealth Chief Medical Officer, the Attorney General and a couple of others drunk at uni together.
But aside from that, you're paying for peers. That $30k cheque you write each year is a filter - "we're keeping out the riff-raff!" Are your peers people whose parents push them towards excellence, or parents who don't expect much of them?
Of course, even the private schools are regulated by government, so people might blame their relative non-performance on that. That's possible, I suppose, but peers do matter a lot.