Comparability · snapshot 2026-08-16
Where the published answers disagree
Two indices, one publisher, one market, one window — and different answers. Both are correct. Neither is the answer, and there is no third number that is.
Is this market expensive compared with its own past?
The two ratios divide the same house prices by different denominators. One asks how many years of household income a home costs; the other asks what it costs against what it would rent for. Incomes and rents do not move together — an economy where wages rose faster than prices and rents lagged both will read cheap against income and dear against rent, and neither reading is wrong.
Neither ratio is the valuation of a market, and there is no third number that is. A reader who takes one and calls it the answer has not simplified the question, they have chosen a denominator without noticing. Where the two point opposite ways, the honest statement is that this market got cheaper by one measure and dearer by the other in the same window.
23 markets publish both readings. 4 of them have the two on opposite sides of their own 2015 — cheaper by one measure and dearer by the other, in the same window. Every market with both readings is listed below. There is no threshold and no shortlist: a page showing only the worst disagreements would let a reader take the rest for agreement.
| Market | Against income | Against rent | Spread | Reading |
|---|---|---|---|---|
| South Korea | 47.8 | 106.2 | 58.5 | They contradict each other |
| Colombia | 94.3 | 150.6 | 56.3 | They contradict each other |
| New Zealand | 125.2 | 170.6 | 45.4 | They agree on direction |
| Norway | 120.1 | 165.4 | 45.3 | They agree on direction |
| Spain | 127.0 | 166.6 | 39.6 | They agree on direction |
| Denmark | 122.4 | 154.5 | 32.2 | They agree on direction |
| Sweden | 119.4 | 145.1 | 25.7 | They agree on direction |
| Germany | 87.9 | 112.0 | 24.1 | They contradict each other |
| France | 106.7 | 128.9 | 22.2 | They agree on direction |
| Japan | 87.8 | 109.5 | 21.7 | They contradict each other |
| Australia | 154.4 | 175.5 | 21.1 | They agree on direction |
| Belgium | 119.6 | 139.9 | 20.3 | They agree on direction |
| Greece | 109.4 | 128.8 | 19.4 | They agree on direction |
| Canada | 141.2 | 159.9 | 18.8 | They agree on direction |
| United States | 111.7 | 130.2 | 18.5 | They agree on direction |
| Netherlands | 141.4 | 157.3 | 15.9 | They agree on direction |
| United Kingdom | 116.6 | 131.4 | 14.7 | They agree on direction |
| Finland | 78.5 | 91.3 | 12.8 | They agree on direction |
| Austria | 122.4 | 111.6 | 10.8 | They agree on direction |
| Portugal | 142.7 | 152.6 | 9.9 | They agree on direction |
| Switzerland | 123.6 | 130.1 | 6.5 | They agree on direction |
| Italy | 90.5 | 93.4 | 2.9 | They agree on direction |
| Ireland | 115.6 | 116.4 | 0.8 | They agree on direction |
What is not on this page
No average, no midpoint, and no combined figure. The type these rows are built from has no field for one, which is deliberate: Korea reads 47.8 against income and 106.2 against rent, and a mean of 77 would describe a market that does not exist while looking like the most confident number here.
The spread is not a severity score and the ordering is not a ranking. It is the size of the disagreement, in index points on each market’s own base, and two markets with the same spread have nothing else in common.
Only one family is declared so far, and it holds two members from one publisher. The disagreements this page cannot yet show are the ones between two different publishers measuring the same thing, which is where the gap is usually widest — and those need a licence read before a figure from a commercial report can be quoted here at all. Recorded in docs/DATA-GOVERNANCE.md rather than left looking unconsidered.