The 'Good Suburb' Myth: The Demographics That Tracked Property Growth Backwards

Every property guide tells you the same thing: buy in the good suburb. High household income, lots of professionals, well-rated schools, a postcode with a reputation. Quality holds its value; quality grows.

Across the last twelve years, in 30 of Australia’s most-targeted markets, every one of those signals tracked growth backwards. The higher the income, the higher the socio-economic score, the better the schools — the slower the suburb grew.

Heyward matched the ABS Census demographics for each market against the 10-year price growth from our own 12-year growth study. The correlations weren’t subtle, and they all pointed the same, unexpected way. Here’s what the census actually shows — and why the “buy in the best suburb” instinct would have picked the laggards.

We correlated the standard “quality suburb” demographics against each market’s 10-year growth. Every prestige signal came back negative — the stronger the signal, the slower the growth:

A correlation of −0.5 or stronger, at this sample size, isn’t noise — it’s a real, consistent inverse relationship. Read the table plainly and it says something the entire “buy the best suburb” playbook gets wrong: the demographic markers of a premium suburb were markers of a slower-growing one. And the one signal investors treat as a direct cause of rising prices — population growth — turned out to have no meaningful link to it at all.

(A note on the data: the demographics are ABS Census-derived; the growth is our own measurement across 30 markets. The school figure is the thinnest — government-school ICSEA was available for 23 of the 30. As always, this is our sample over one particular period, not a law of the universe, and correlation isn’t causation — which §04 is about.)

Split the markets into thirds by each prestige signal and the pattern is impossible to miss — the “better” third grew slower every time:

An investor who screened on income — “I only buy in the top suburbs” — would have systematically selected the markets that grew at half the rate. Priced into a single property over ten years, that’s not a rounding error:

$700,000, 10 years:
  Top-income suburb (3.14%):     $700,000 × 1.0314¹⁰ = $954,000
  Bottom-income suburb (6.53%):  $700,000 × 1.0653¹⁰ = $1,318,000
                                                       ───────────
  Cost of buying "the best suburb":                     $364,000

The prestige postcode didn’t just grow a little slower. On the same starting money, it left $364,000 on the table over a decade — the price of buying a reputation instead of a rate.

“People are flooding into this area, so prices have to go up” might be the most repeated rationale in property — and one of the weakest. Across our markets, 10-year population growth correlated −0.13 with price growth: no meaningful relationship, and if anything a faint inverse one.

The reason is supply. The suburbs absorbing the most people are frequently the ones approving and building the most dwellings to house them — outer-ring estates, mid-rise infill, master-planned corridors. That new stock soaks up the very demand that’s supposed to lift prices. Population growth tells you a place is in demand; it tells you nothing about whether supply is keeping pace, and price growth lives entirely in that gap. A growing suburb with a building boom can be flat for a decade.

None of this says wealth holds a suburb back. The mechanism is simpler, and it’s entirely about price level.

A high-income, high-SEIFA, top-school suburb is — almost by definition — one that has already been bid up. It carries a high price base relative to incomes, which leaves less room to run. The affordable suburbs didn’t grow because they were cheap in some moral sense; they grew because they were catching up from a low base while the premium markets sat near their affordability ceilings. It’s the same story the capital cities told — Sydney and Melbourne, the most prestigious markets, grew the slowest — now visible through the census instead of the price table.

So the demographics aren’t a cause. They’re a marker of a price level that has already happened. Which is exactly why they make a poor forecast: by the time a suburb looks unmistakably “good” on the census, the growth that earned it that profile is mostly behind it.

That doesn’t make demographics useless — far from it. Income and occupation tell you who your tenant is and how secure the rent is; school catchments support demand and resale. Read them for what a suburb is. Just don’t read them for where it’s going — for that, you need the starting price relative to the market, the supply pipeline, and the actual long-run growth rate, not the prestige of the name on the sign.