Methodology

The central problem with sauna import research is classification ambiguity. Our method starts with that limitation rather than hiding it.

1. A category enters the tracker only with sauna evidence

We begin with U.S. Customs and Border Protection rulings involving an identifiable sauna product or component. A ruling establishes that a particular product, under the facts presented, was classified in a particular tariff provision.

2. We retrieve official Census trade statistics

The automated job queries the U.S. Census Bureau International Trade API. Census describes its monthly international-trade datasets as current-month and year-to-date import and export statistics available from January 2010 onward. The site stores the results as static JSON/CSV so every visitor receives the same published snapshot.

3. We do not turn broad categories into false sauna totals

HTS 9406.10.0000 covers prefabricated buildings of wood, not only saunas. HTS 8516.29 covers other electric space-heating apparatus, not only sauna heaters. HTS 8516.79 covers other domestic electrothermic appliances, not only portable infrared saunas. Adding their full values would create an impressive-looking but misleading number.

Therefore: each series is published independently as a “sauna-relevant tariff category.” Sauna Import does not currently publish a Census-derived total U.S. sauna import market size.

4. General imports vs. imports for consumption

The dataset retains both Census measures where available. General imports reflect goods entering the U.S. customs territory, while imports for consumption are the goods entered for immediate consumption plus warehouse withdrawals for consumption. Analysts should choose the measure that fits their question rather than treating the terms as interchangeable.

5. Automation

A scheduled GitHub Action queries the API, locates the newest available trade month, retrieves a rolling 36-month world series for each configured category, and retrieves the latest origin-country breakdown. It commits the new static dataset only when the values change.

6. Failure behavior

If the API returns ambiguous duplicate rows for the same category, month or country with conflicting values, the updater stops rather than silently combining them. Stale data are preferable to fabricated precision.

7. What would improve the dataset

The next level is shipment-description data capable of identifying sauna-related bills of lading within broad HTS categories. Any such source should be added only if licensing, reliability and reproducibility are acceptable.