Retail brand density

Definition

Retail brand density is a count of specific brand storefronts and OSM-tagged amenities per 100,000 residents. We compute separate metrics per brand (Starbucks_per_100k, Walmart_per_100k, etc.) and per category (cafes_per_10k, restaurants_per_10k, breweries_per_10k).

Source data

• OpenStreetMap (Overpass API) — User-contributed map data with brand tags + amenity classifications (2026 snapshot)
• Census ACS Population — Place-level population for the per-capita denominator (2019–2023)

Steps

1. Run an Overpass API query against each tag combination of interest (e.g., brand=Starbucks, amenity=cafe).
2. Geolocate each result to its containing ZCTA via spatial join.
3. Aggregate count per ZCTA.
4. Divide by ACS population to compute per-100k or per-10k.
5. For places spanning multiple ZCTAs, sum the counts and divide by the place population total.

Known limitations

• OpenStreetMap coverage varies geographically; urban areas have more complete brand tagging than rural ones.
• Brand names are tagged inconsistently ("Starbucks" vs "Starbucks Coffee"); we apply tag normalization but may miss outliers.
• Closed locations are not always removed promptly; the count reflects the most recent OSM contributor edit.
• Drive-throughs and inside-Target locations may or may not be tagged depending on the contributor.
• Hyper-rural places with <1,000 residents have small denominators producing volatile per-capita rates; we suppress values for pop < 500.

Where this metric appears

Every place page (where data exists), Coffee-per-capita list, the Brewery density list, and similar.

Related methodology

• Coffee culture index
• Amenity diversity

Cite this methodology

Commerce Institute. (2026). Retail brand density — Methodology. Retrieved from https://commerceinstitute.org/methodology/retail-density/.