How Every U.S. County Is Classified Each Month
Each month, every county in the dataset is put through the same short sequence: find its price series, measure recent change and distance from its high, apply fixed rules and attach a confidence score. This explainer walks through the sequence in plain steps so you can see where each label comes from.
- Every county follows the same pipeline each month, so labels are comparable across the country.
- The pipeline uses two measurements: year-over-year price change and drawdown from peak.
- The output is a phase label plus a 0-100 confidence score.
- County price series may come from a metro, non-metro or state index.
Step one: attach a price series
Each county is matched to the price index that covers it. Where a county-level measure exists, it is used; elsewhere the county takes the index of its metro area, a non-metro grouping or its state. This step determines which history the county will inherit, and it is why neighbouring counties sometimes share identical numbers. Where several counties are assigned one series, they will move in unison, which is simply a consequence of the data available.
Step two: measure speed
From the latest reading, the pipeline computes the year-over-year change by comparing it with the same month a year earlier. That figure captures direction and pace without seasonal distortion. It is the first of the two inputs, and it answers whether prices are rising, falling or roughly flat compared with last year.
Step three: measure distance from the high
Next the pipeline finds the highest value in the series and compares the current reading to it. The percentage gap is the drawdown. A county at its record has zero drawdown; one deep below has a large value. This second input captures memory of past levels, which the annual change cannot provide.
Step four: apply the rules
With speed and distance in hand, fixed rules assign a phase. Strong positive speed near a high points to expansion or peak, negative speed with a widening gap to contraction, turning speed below a high to recovery, and quiet readings to neutral. The same rules run for every county, which keeps results consistent and free from individual judgment.
Step five: score the fit
Finally, the pipeline records how comfortably the readings sit within the chosen phase's boundaries as a 0-100 confidence score. The result, refreshed monthly, is a label and a score for each county. Because everything is computed from the series, anyone with the same inputs and rules would reach the same answer. The simplicity is deliberate, since a short pipeline is easier to inspect, repeat and explain than a sprawling one.
The latest reading
The June 2026 run classified 3,150 counties across 51 states, drawing on 1,046 metro-area, 1,308 non-metro and 796 state price indexes.
How Every U.S. County Is Classified Each Month: questions
How often are counties classified?
Each run recalculates year-over-year change, drawdown and the confidence score for every county using the latest price index data.
Are all counties treated the same way?
Yes. The same inputs and rules apply to all counties. Differences in labels arise from price data, not from case-by-case judgment.
What are the inputs to the classification?
Two measurements from the county's house price index series: year-over-year change and drawdown from its prior peak.
Where does a county's price series come from?
From the metro-area index that covers it, a non-metro index or its state index, depending on what data exist for that county.