Appliance Price Index — methodology

What the Appliance Price Index measures

The index tracks the price movement of a fixed set of individual refrigeration models, expressed relative to a base month set to 100. A category reading of 100 means the same as the base month; a reading below 100 means the matched models are cheaper on balance than at the base month, and a reading above 100 means they are more expensive. Because the index follows the same models month to month, it isolates real price change from shifts in which products happen to be listed.

How the matched-model method works

An average of every price listed in a month is misleading, because the mix of products changes: add a few high-end models and the average rises even if no single price moved. The index avoids that by comparing each model only against itself. For every pair of consecutive months, only models that have a valid price in both months count, and the index moves by the geometric mean of those models’ month-over-month price ratios. Retailer duplicates and finish variants of the same appliance are collapsed into one model before matching, so a product listed at several stores is counted once.

A model’s monthly price is the median of its daily prices within the calendar month, so a single-day spike or dip does not swing the figure. Prices outside $20.00 to $30,000.00 are treated as data errors and dropped, and month-over-month ratios outside 0.5× to 2× are dropped as artifacts. There is no imputation of missing prices and no seasonal adjustment in this version.

Where the data comes from

The index is built from two of Fridge.com’s own data stores: the live product catalog of active refrigeration appliances, which defines the set of models tracked, and NEW-condition price history for those models collected from Amazon through Keepa, which supplies the prices. No third-party index, survey, or estimate is used. In this version the price history is NEW-condition Amazon data only; a separate retailer price-history series is not included because that source table is absent from the current database. The source used is recorded for every price point.

How current the data is

The index is computed by calendar month. Each month’s figure is settled after the month closes, and the dataset metadata records the exact computation timestamp and the methodology version so any release can be dated precisely. This release covers through June 2026 and was computed in July 2026 under methodology version 1.0.0-draft. The published window is floored at May 2024; deeper price history exists but is not published, to keep the survivorship bias of building a matched-model index on the current catalog bounded.

Latest published index by category

16 categories clear the publication threshold of at least 30 matched models. Each row shows the most recent qualifying month, the index for that month (base month = 100), the number of matched models behind it, and the median model price.

Categories below the publication threshold

These categories do not yet have enough matched models to publish an index figure, so no index value is reported for them. They are listed for completeness only.

• Compact freezers: 6 matched models, below the 30-model minimum.
• Counter-depth refrigerators: 13 matched models, below the 30-model minimum.

Known limitations

• Amazon-NEW-centric: the NEW-marketplace price is the only priced source; no retailer series in v1 (price_snapshots table absent).
• Matched-model set is survivorship-limited to models in the current active catalog that carry Keepa history; the published window floors at 2024-05 to keep this bias bounded.
• History depth differs by model; a model contributes only to months in which it has ≥ 5 daily observations.
• All matched models are weighted equally; the index measures list-price movement, not sales-weighted realized price.

Appliance Price Index FAQs

Related pages

• Fridge.com Data
• Appliance Price Index tables
• Appliance Price Index methodology
• Download the index as CSV