Data Sources
Every metric on homestats.app comes from a public dataset you can verify yourself. This page is the dictionary of those datasets: what we pull from each one, at what grain, and how often it refreshes. For the formulas we compute on top of them, see the methodology.
Primary Data Sources
All data is public domain or used under each agency's open-data terms with attribution. Pipeline source code: scripts/fetch-data.mjs.
| Source | What we pull | Grain | Update cadence |
|---|---|---|---|
| Redfin Data Center | Median sale price, inventory, days on market, price drops, sale-to-list ratio, homes sold, months of supply — split by All Residential / Single Family / Condo | National, state, county, city, ZIP | Weekly TSV refresh |
| FRED (St. Louis Fed) | 30-yr + 15-yr mortgage rates (MORTGAGE30US, MORTGAGE15US), serious delinquency (DRSFRMACBS), housing starts (HOUST), existing home sales, unemployment (UNRATE), CPI (CPIAUCSL); state permits (XXBPPRIV) and state unemployment (XXUR) | National + 50 states | Daily–monthly depending on series |
| FHFA House Price Index | Quarterly HPI, mortgage performance | National + state | Quarterly |
| Census ACS 5-year | B19013 (income), B01003 (population), B25002 (vacancy), B25003 (tenure), B25034 (year built), B25007 (homeowner age), B07001 (mobility) | State + 3,142 counties | Annual ACS release |
| HUD Fair Market Rents | Studio / 1BR / 2BR / 3BR / 4BR FMRs | State + metro | Annual (FY) |
| BEA Regional Price Parities | Cost-of-living index relative to U.S. = 100 | State | Annual |
| FBI UCR / Crime Data Explorer | Violent + property crime rates per 100,000 | State (UCR 2022 fallback when API down) | Annual |
| EPA SDWIS | Drinking water quality violations | State | Quarterly |
| FEMA National Risk Index | 18 natural hazard types, expected annual loss | State + county | Periodic refresh |
| FEMA NFIP | Flood insurance policies + claims totals | State | OpenFEMA continuous |
| FEMA Disaster Declarations | Federally declared disaster counts | State | OpenFEMA continuous |
| EIA | Residential electricity prices ($/kWh) | State | Monthly |
| NOAA Climate | Climate normals, average annual temperature | State | 30-year normal |
| Zillow ZORI | Observed Rent Index, smoothed all-homes (metro CSV → state mean) | Metro → state rollup | Monthly |
| NAIC | Average homeowners insurance premium | State (static table) | Annual |
| Tax Foundation | Effective property tax rates | State (static table) | Annual |
| IRS SOI Migration | Net inflow / outflow + top inbound/outbound states (state pages only) | State (static table) | Annual |
| BLS OES | Occupational employment + wages by state | State | Annual |
Derived Metrics — Formulas
This page is the dataset dictionary: what we pull, from where, at what grain, how often. The formulas for everything we calculate on top of those datasets now live in one place, alongside the assumptions baked into each one and an honest note on where each is weakest.
Read the full methodology → — price-to-income and price-to-rent and the benchmark they are measured against, plus buy-vs-rent, the single-family vs condo gap, inventory surplus, days-on-market spike, the HomeStats market score, and boomer and millennial owner share.
Further Reading & Cross-References
Research bibliography, not a shopping list. These are the outlets we read and check our own output against: different cuts of the same underlying data, institutional research, and a few commercial datasets that are worth knowing exist even where the licensing puts them out of reach. We have no relationship with any of them, and nothing here is an endorsement.
If what you actually want is a side-by-side of which free sources cover what, that is a different question and it has its own page: free housing data compared, feature by feature.
| Site | What it offers | Pricing |
|---|---|---|
| Reventure App | Nick Gerli's housing dashboard with proprietary Crash Risk Score, Buyer Demand Score, ZIP-level forecasts, migration heat maps | Subscription |
| NeighborhoodScout | Neighborhood-level appreciation history, school + crime detail, demographic profiles, real-estate-investment scores | Subscription |
| Zillow Research | ZHVI, ZORI, market reports, methodology PDFs, market heat index | Free |
| Realtor.com Economic Research | Active inventory, listing trends, hottest markets ranking | Free |
| ATTOM Data | Foreclosure activity, investor share, cash sales | Paid (cited by reporters) |
| CoreLogic Intelligence | HPI, delinquency, fraud risk, climate risk | Paid |
| ICE / Black Knight Mortgage Monitor | Monthly mortgage performance, servicing data | Free PDFs |
| Harvard JCHS | State of the Nation's Housing annual report | Free |
| NAHB Economics | Builder sentiment, regional starts, cost surveys | Free |
| NAHB Eye on Housing | NAHB economist blog, permits + starts deep-dives | Free |
| Calculated Risk | Bill McBride's housing-data commentary, weekly inventory tracking | Free |
| Altos Research | Weekly active-market data, listing-side metrics, video analyses | Free + paid |
| Parcl Labs | Daily price indices and inventory by market | Free + paid |
| Census SAHIE / SAIPE | Small-area health insurance + income/poverty estimates by county | Free |
| Urban Institute Housing Finance Policy Center | Monthly Housing Finance Chartbook, mortgage performance research | Free |
What We Don't Have (Yet)
- Investor / cash-buyer share at the local level — requires ATTOM, CoreLogic, or PropMix licensing. Free public sources don't publish it at granularity below the metro level.
- County-level mortgage delinquency — FRED has national + state series; county requires CoreLogic / Black Knight.
- School ratings — GreatSchools is the de-facto source and requires a partnership.
- Walk Score / Transit Score — requires a Walk Score API license.
- Proprietary composite forecasts — our position is that transparent metrics (DOM spike, inventory surplus, value ratios, SFR-vs-condo gap) are easier to verify than black-box composite scores. We may add a HomeStats composite later, but we'll publish the formula.
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