Market Analysis
Part of Understanding the Australian retail market
Separating nominal sales growth from changing prices
Read Australian current-price spending beside matching volume measures without mistaking higher spending for more units sold.
A rise in retail dollars does not by itself mean more goods or services were bought. Current-price, or nominal, growth reflects prices, measured volume and changes in what is bought. Where a matching volume series exists, read the two together for the same category, place and period.
Read current price and volume together
The ABS MHSI methodology describes quarterly chain-volume estimates. Chain volume removes the direct effects of price changes from the measured aggregate. If current-price spending rises while volume is flat, those extra dollars do not represent growth in measured volume.
For a hypothetical arithmetic illustration, 100 identical items sold at $10 each produce $1,000 in sales. Selling 100 at $11 produces $1,100: nominal sales rise 10%, while the item count stays at 100.
Real categories contain changing products, quality and mix. An official chain-volume result is not an item count for every shopping basket.
Nominal Sales Growth vs. Chain-Volume Growth: Key Differences
- Nominal Sales GrowthReflects price changes, volume and product mix; does not indicate actual increase in units sold.
- Chain-Volume GrowthRemoves price effects using quarterly chain-volume estimates; measures real change in volume.
Match the series
Compare a quarter’s current-price movement with that quarter’s chain-volume movement for the same category and geography. Keep the original or seasonally adjusted basis consistent. A single nominal month and a quarterly volume change cannot be subtracted to obtain inflation.
Check that the matching series is actually published. The ABS methodology describes quarterly chain-volume estimates and says outputs from nine COICOPs and all states and territories are published. Estimates can be revised, so keep the release date with a quoted growth rate.
A short reading record needs the nominal change, the matching volume change, the period and adjustment basis, and the coverage limits. When discussing an aggregate, say “measured volume”, not “number of items sold”.
How to Correctly Interpret Retail Spending Data
- Identify matching nominal and chain-volume series for the same category and geographyEnsure both are on the same adjustment basis (original or seasonally adjusted).
- Check publication status and release dateConfirm the data is published and note any revisions; avoid using unverified or provisional figures.
- Compare movements over the same periodDo not subtract monthly nominal from quarterly volume; use aligned timeframes.
- Use official chain-volume results for analysisAvoid applying headline CPI to all categories; prefer matched ABS published series.
Use a relevant price measure
The ABS incorporates monthly CPI changes into the price deflators used to produce quarterly chain-volume estimates. Applying headline CPI to every retail category would use a different basket. Prefer the published matching chain-volume series where available.
For matched nominal and volume indexes over the same interval, their ratio can imply an aggregate price movement. Simply subtracting their growth rates is an approximation because percentage changes compound. Neither calculation shows that every product’s shelf price changed by that amount.
Key ABS Data Points for Household Spending Analysis
- Price Deflators Source
- Monthly CPI data incorporated into chain-volume estimates
- Published Chain-Volume Estimates
- Available for nine COICOPs and all Australian states/territories
- Adjustment Basis Consistency
- Must match between nominal and volume series (original or seasonally adjusted)
Keep the conclusion bounded
Volume growth helps answer whether price-adjusted spending increased. It does not show that every customer bought more units, and chain-volume components generally cannot be added as ordinary dollar amounts.
To explain one retailer’s revenue growth, use suitable information on its prices, units and product mix. National household spending supplies context, not that retailer’s decomposition.
