1. The Problem with Simple Median Sales Prices
Mainstream media frequently reports changes in property values using “median sales price.” However, simple medians are notoriously flawed indicators for serious real estate investors because of compositional bias:
- Example of Bias: Suppose in Month 1, 100 beachfront luxury properties sell in Sydney’s Eastern Suburbs, resulting in a median sales price of $2,200,000. In Month 2, luxury transactions dry up, but 300 entry-level apartments settle in Western Sydney, dragging the median price down to $780,000.
- The False Conclusion: A simple median would falsely report that the market crashed by 64% in a single month. In reality, not a single individual property lost value—the composition of transacting stock simply changed.
2. How Hedonic Regression Eliminates Composition Bias
The CoreLogic Home Value Index controls for composition by breaking down every transacting property into a mathematical bundle of distinct attributes:
- Physical Attributes: Number of bedrooms, bathrooms, car garage spaces, total land area, and internal living floor space.
- Geographic Location: Distance to central business district (CBD), coastline proximity, transport hubs, and local school catchment rankings.
- Historical Trajectory: Historical sales prices and capital appreciation history of comparable surrounding dwellings.
By weighting these variables through multi-variable econometric regression, the index measures the pure change in asset value, isolating genuine market appreciation from shifting transaction volume types.
| Index Metric | What It Measures | Strategic Use for Property Investors |
|---|---|---|
| Monthly Index Movement | Change in pure valuation over the prior 30 days. | Monitors short-term sentiment shifts and early inflection points. |
| Rolling 3-Month Change | Quarterly price momentum smoothing monthly noise. | Primary benchmark to determine market acceleration or slowdown. |
| Stratified Tiers (Lower/Middle/Upper 25%) | Price movements segmented across valuation quartiles. | Identifies whether luxury or entry-level stock is driving growth. |
| House vs Unit Index Disparity | Separate hedonic tracking for detached land vs strata apartments. | Informs portfolio asset allocation between houses and units. |
3. How to Spot Market Turning Points Using HVI
Professional property analysts track the rate of change (first derivative) of the rolling 3-month index. A market transition rarely happens overnight; it progresses through distinct phases:
- Deceleration Phase: 3-month rolling growth slows from +3.5% to +1.8%, then to +0.4%. While values are still rising, momentum is exhausting.
- Peak & Flattening: The monthly index hovers between ±0.1% for two consecutive months as auction clearance rates drop below 60%.
- Contraction Phase: Rolling 3-month growth prints negative (−0.5% to −1.5%). Vendor discounting widens, and days on market extend past 35 days.
Frequently Asked Questions
Does the CoreLogic Index cover private off-market sales?
Yes. The CoreLogic index ingests sales records directly from state government Valuer-General titles offices across Australia upon settlement, capturing all off-market, private treaty, and public auction transactions.
What is the difference between CoreLogic and SQM Research asking price indices?
CoreLogic measures settled historical property valuations using hedonic regression. SQM Research measures the weekly asking prices advertised by vendors on real estate portals. SQM provides a forward-looking indicator of vendor sentiment, while CoreLogic measures settled transaction reality.
- Review current city divergence metrics in our recent capital city home value index benchmarks.
- Track macro lending effects driven by monetary policy transmission from the RBA cash rate.
- Find technical econometric terms explained in hedonic index definitions in our glossary.