House Price Index YoY

The FHFA House Price Index YoY measures US home prices versus the same month or quarter 1 year earlier. It comes from FHFA, the Federal Housing Finance Agency, the US agency overseeing Fannie Mae and Freddie Mac. Its headline Purchase-Only series tracks the same single-family homes over time using only sales prices. It draws on more than 100 million sale and refinance transactions and reports seasonally adjusted nominal change.

The series began in 1995 and rests on records reaching back to 1975. It covers the nation, nine divisions, 50 states and metro areas. It does not measure average or median prices, rents or inflation-adjusted prices, and it differs from Case-Shiller in data and method.

FHFA publishes a monthly report every month and a larger quarterly report every 3 months. Releases arrive at 9:00 AM Eastern Time on Tuesdays, normally in the last week of the month, about 2 months after the reference period. The transaction date is the loan origination date, so monthly pairs pool into one value and quarterly pairs pool with no split by month. Each release brings a press release, tables, figures, downloadable files, a calculator, maps and a top-100 metro ranking.

FHFA revises history back to 1975 each release as new pairs, older loan purchases and the 30 to 45 day data lag add information. Readers follow % changes, not levels, with gains for rise, losses for fall, and no threshold line.

The national YoY has no fixed spending weights and aggregates regional growth by housing stock.

• Purchase-Only HPI: captures sales-price change for conforming conventional loans bought by Fannie Mae and Freddie Mac.
• All-Transactions HPI: adds refinance appraisals to the purchase-only sales sample.
• Expanded-Data HPI: adds FHA loans and county records, including cash and larger loans, to approximate the whole market.
• Distress-Free HPI: removes short sales and bank-owned sales to show prices without distressed deals.
• State and division indexes: track repeat-sales growth for each state and for 9 multi-state regions used to build the nation.
• Metro and local indexes: cover metro areas, counties, ZIP codes, census tracts, Puerto Rico and manufactured homes for local detail.

In the 2024Q1 example, published May 28, 2024, US prices rose 6.6% from 2023Q1 and 1.1% from 2023Q4. The March monthly index rose 0.1% from February. Gains covered all 50 states, led by Vermont at 12.8% and New Jersey at 11.6%, while the District of Columbia fell 1.5%.

Middle Atlantic led divisions at 9.9% while West South Central trailed at 3.7%, and 97 of the top 100 city areas rose. Allentown led at 16.0% while Honolulu fell 3.2%, as low for-sale inventory supported growth despite mortgage rates near 7%.

1. Repeat pairs: FHFA matches two transactions for one address using loan start dates and pools pairs by month or quarter.
2. Market level: FHFA estimates the market price level for each month or quarter from all pairs together. For example, a $300,000 purchase and later $360,000 sale gives a log change of about 0.1823.
3. Weights: Pairs with short gaps get more weight since prices drift more over long gaps. For example, a 1-year gap gets about 3 times the weight of a 3-year gap.
4. Index and aggregation: The index sets a base period equal to 100 and turns market levels into index numbers. States and regions combine by growth rates using housing-stock shares, where 8% at 0.6 weight plus 5% at 0.4 weight gives 6.8%.
5. Seasonal adjustment: FHFA removes normal seasonal patterns with the Census X-13 filter.
6. Year-over-year arithmetic: The 12-month change divides the index gain by the level 12 months earlier. For example, index 400.0 versus 375.0 a year earlier gives (400.0 minus 375.0) divided by 375.0, or 6.67%.