TCBI + TSCI — Methodology & Sources

Live federal data. State baseline × tract_fc, clamped [0.7, 1.5]. Every value carries provenance. 2026-05-12 publication snapshot

What these tools are

TCBI — True Cost Basket Index. Five-domain weekly household basket cost (D1 Pump, D2 Pantry, D3 Plate, D4 Restaurant, D5 Composite + Income-share) across all 50 states, DC, and 3,142 US counties. Tract resolution (Census ACS5 2023) for 15 mega-counties covering ~17% of US population, plus 262 NYC Neighborhood Tabulation Areas across all 5 boroughs.

TSCI — True Shelter & Family Cost Index. Fixed monthly shelter nut (D1 Rent, D2 Mortgage, D3 Insurance HO/RE, D4 Childcare via DOL NDCP) across 3,222 US counties + Puerto Rico. County-level resolution. 21 BLS CPI metro outline overlay.

Federal data sources

SeriesIdentifierUsed for
Census ACS5 2023 — Median Gross RentB25064_001ETCBI tract_fc; TSCI D1 Rent
Census ACS5 2023 — Median Home ValueB25077_001ETSCI D2 Mortgage baseline
Census ACS5 2023 — Owner Costs with MortgageB25088_001ETSCI D2 monthly P+I+T+I
Census ACS5 2023 — Household IncomeB19013_001EIncome-share, burden calcs
Census ACS5 2023 — Total PopulationB01003_001EPop-weighted state/NTA aggregations
EIA Weekly Retail GasolineEMM_EPMR_PTE_* (PADD + state)TCBI D1 Pump
BLS Average Price Data (regional)APU0000FF1101 familyTCBI D2 Pantry · 4 Census regions
BLS APU Mediterranean basket10 LIVE + 7 SYNTH-ANCHORTCBI D3 Plate · weekly fam-of-4
BLS CPI Food Away From HomeCUUR0000SEFVTCBI D4 Restaurant · national base
USDA Thrifty Food Plan Sept 2024FNS reference tableTCBI D3 calibration anchor
DOL NDCP — Childcare PricesWomen's Bureau 2018 (inflation-adj)TSCI D4 Childcare · all 50 states + PR
NAIC HO-3 / HO-42022 Annual Report tablesTSCI D3 Insurance · state-level premiums
us-atlas counties-10m.json + states-10m.jsonnpm us-atlas@3National/state choropleth geometry
loganpowell/census-geojson 2020 cb_500kraw GitHub via jsdelivrTract polygons (TCBI mega-counties)
NYC DCP Neighborhood Tabulation Areas 2020NYC Open Data 9nt8-h7nd262 NYC NTA polygons
Census ZCTA→County Relationship Filetab20_zcta520_county20_natlTSCI ZIP search (33,791 mapped)

Core formulas

TCBI — tract-level value

tract_value = state_baseline × tract_fc

where tract_fc = tract_median_rent / state_avg_median_rent, clamped to [0.7, 1.5].

For D1 Pump (non-housing-correlated): tract_fpump = 1 + 0.5 × (tract_fc − 1) (damped).

TCBI Composite (D5): 0.4 × pump + 0.6 × housing-correlated.

TSCI — county-level burdens

owner_nut = owner_cost + cc_m + ho_ins/12

owner_burden % = (owner_nut × 12) / median_HH_income

renter_burden % = (rent × 12) / median_HH_income

P/I = median_home_value / median_HH_income

TSCI Composite (ti): weighted aggregate, pop-weighted at state/national.

NYC NTA aggregation

NTAs are not Census tabulation units. Tract-level ACS5 values aggregate up to NTA via point-in-polygon (tract centroid in NTA boundary), pop-weighted mean. Coverage: 2,293 of 2,324 NYC tracts mapped (98.7%). Suppressed tracts inherit county value.

Provenance flag taxonomy

LIVE-EIA-STATE direct EIA state-level series LIVE-BLS-REGION direct BLS regional APU value
LIVE-ACS-TRACT direct Census ACS5 tract value LIVE-DOL-NDCP direct DOL childcare county value
LIVE-NAIC-STATE direct NAIC HO-3/HO-4 state premium PROXY-PADD/REGION state inherits PADD or Census region value
PROXY-COUNTY-ADJ county via rent ratio fc PROXY-TRACT-ADJ tract via tract rent ratio (clamped)
PROXY-STATE-FLAT county inherits state value flat TCBI-TRACT-DERIVED composite at tract via weighted formula
COUNTY-LEVEL no tract data exists (D4 inherits county) DATA-SUPPRESSED ACS small-N suppression — fall back

Vintage timeline

SourceThis snapshot usesReleasedNext refresh
Census ACS5 (rent, income, home value, pop)2023 vintageDec 2024ACS5 2024 → Dec 2026
EIA Weekly Retail Gas2026-05-112026-05-12weekly Mondays
BLS APU/CPI (Pantry, Plate, Restaurant)2026-M032026-04-15monthly mid-month
USDA Thrifty Food PlanSept 20242024-09quadrennial
DOL NDCP Childcare2018 base (inflated to 2023)periodicwhen DOL publishes
NAIC HO-3 / HO-42022 Annual Report2024-01annual
NYC DCP Neighborhood Tabulation Areas2020 vintage2020~decennial

Known constraints

Clamps. tract_fc ∈ [0.7, 1.5] produces visually-flat regions in very-low-rent (rural) or very-high-rent (Manhattan) areas. Intentional limit on baseline extrapolation; documented in audit workbook's Calibration_Audit sheet.

D4 Restaurant at tract level. BLS CPI Food Away From Home has no published tract-level series. Tract inherits county value flat. Flagged COUNTY-LEVEL.

TSCI suppressed slots. 8 states (AR, CT, IN, MO, NM, PA, VT) + Puerto Rico are proxy-derived for one or more DOL NDCP childcare slots. TSCI Insurance is NAIC state-only — no county detail exists in published data.

Curated place seeds. TCBI's place mid-tier uses 177 curated seed centroids (LA Beverly Hills, Cook Hyde Park, etc.) with Voronoi tessellation. Real TIGER PLACE polygons deferred to a future vintage.

Suppressed tracts. 72 of 2,498 LA County tracts (~3%) have suppressed ACS5 rent data due to small-N; they fall back to CA state composite with the DATA-SUPPRESSED flag.