How We Scored History
Every month of Arizona’s luxury market, 2007–2026, under the published methodology
The index went live in August 2026. Everything before that is a reconstruction: the frozen methodology run backward across the complete MLS record — the same construction, the same seasonal correction, the same norm. These pages did not exist contemporaneously, and each one says so. That is precisely what makes them checkable: the method is published, the full series is downloadable (CC BY 4.0), and anyone with the data can reproduce every number. Each month is measured against its own trailing five-year norm — the market as it stood in the five years just before it. So 2018 is judged against 2013–2018, and reads the way it was actually lived, rather than against a single fixed era that would make every calm year look broken. New months of the reconstruction release weekly until the record is complete; the issue archive holds everything published live since launch.