Exhibit 01 · 2021 → 2026
The $1.05 chicken that vanished
In November 2021, a pound of chicken breast cost $1.05 at Key Food and $15.99 at Food Story, six blocks apart. That 15.23× spread was the widest in the corpus, and the $1.05 sat 70.98% below the national average: consistent with a sale price caught on visit day. Toggle to 2026 and the anomaly is gone. Every store prices between $5.99 and $10.99, and the neighborhood median runs 67.2% above the national average.
Cheapest chicken breast per store, Nov 2021 ($/lb, log scale)
Hollow circle = sale-suspect observation. Dashed line = BLS national average (fully labeled). Tap a store for its receipt line.
Read the fine print (7)
- The 15.23× spread is a quality-mix spread, not a like-for-like markup: the endpoints are a conventional store brand (Urban Meadow) versus a natural market's single premium option.
- Key Food's $1.05/lb is 70.98% below the BLS national average ($3.618/lb, Nov 2021) — consistent with a sale price on visit day. Retroactive proof is impossible from this corpus.
- 2021: Mr. Fruit Stores listed $13.99 per pack, unit unstated — excluded from the per-lb comparison. Hana Natural and Shop Fair carried none.
- 2026: chicken breast not carried at Hana, Brooklyn's Natural, or Food Story. Thin-sliced cutlets at 4 stores carry a per-lb premium over whole breasts by construction, so the 2026 level is overstated; the "no loss-leader" conclusion is safe, the +67.2% premium is soft.
- Mr. Lemon's $10.99 is D'Artagnan, regeneratively raised — flagged MISMATCH against the reference product.
- BLS figures are national averages, not NYC-metro item averages; single visit per store in every survey.
- Verdict per the 2026 analysis (B7): 7.61× Key Food's 2021 price against BLS breast +15.56% over the window — the durable-everyday-$1/lb reading of 2021 is dead; the visit-day sale remains the surviving explanation.
Reproduce: python3 analysis/scratch_compute.py · python3 analysis/scratch2_compute.py
View the data
Exhibit 02 · 2021
The brand tax is bigger than the store tax
Switching stores changes your grocery bill by 2.5× to 3× on most staples. Choosing the premium brand on the same shelf changes it by up to 8.21×. The 2021 survey printed a low and a high for each item at each store; every bar below is one shelf. Tap a bar for the brand names behind it.
Mean within-store high÷low ratio per item (open-ended and unit-mismatch rows excluded from means). Coffee ratios are directional: pack sizes unstated. Tap an item to filter the shelves below.
Cheapest vs priciest option on the same shelf, Nov 2021
One bar per store-shelf, sorted by ratio. Fading end + "+" = open-ended "$X and up" range; no maximum was printed and none is drawn.
Read the fine print (6)
- Coffee pack sizes are unstated in the source, so coffee ratios are directional in per-unit terms (chip: DIRECTIONAL).
- Open-ended rows ("$7.99 and up" at Hana, "$7.99 and up" at Met Fresh, "$8.39 and up" at Billy's) are valid floors only; the missing maxima are never drawn.
- City Fresh's milk row lists a gallon price under the half-gallon heading (chip: UNIT MISMATCH); its ratio is excluded from the item mean.
- Key Food's chicken low is the $1.05 sale-suspect from Exhibit 1.
- Associated is excluded: 5 of its rows are verbatim duplicates of Billy's in the source article (DUPLICATE DATA).
- Highs are absent for several stores; the range is what the article printed, not the full shelf.
Reproduce: python3 analysis/scratch_compute.py
View the data
Exhibit 03 · 2026
The 2026 shelf, item by item
The YJC index pinned one reference product per item and priced it at all 12 stores: 21 items, 245 priced observations, sales and comparability flags recorded. Pick an item. Solid mark = effective price (the sale price when lower). Whisker to a hollow tick = the shelf price before the sale. Tap a store row for the full receipt line.
Read the fine print (7)
- Single visit per store; effective prices embed visit-day sales (13 real discounts totaling $21.68 across the survey).
- One product recorded per store, so item medians overstate a cheapest-available premium; floors are the conservative bound.
- Comparability across the 252 rows: 156 OK · 39 Different · 42 Unclear · 15 Mismatch. Spread ratios whose endpoints are flagged are printed in italics.
- Eggs: Met Fresh's price is an 18-pack (MISMATCH as plotted; the analysis adjusts it to per-dozen separately). Billy's $1.67 is a 3-for-$5 sale.
- 7 of 252 rows are not carried (tofu at 3 stores, chicken breast at 3, beer single-bottles-only at Mr. Lemon) and render as dashed "not carried" slots, never as $0.
- 67 of 252 rows carry no collection date (all rows at Brooklyn's Natural, Food Story, Whole Foods, plus 4 others); their tooltips say so.
- BLS reference lines are national averages, not NYC-metro; they are drawn only where the item's unit matches the BLS series (eggs per dozen, boneless breast per lb). Milk is organic half-gallons and is never compared to the conventional-gallon BLS series.
Reproduce: python3 analysis/scratch2_compute.py
View the data
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