House Price Index - HPI

A broad measure of the movement of single-family house prices in the U.S. Apart from serving as an indicator of house price trends, the House Price Index (HPI) provides an analytical tool for estimating changes in the rates of mortgage defaults, prepayments and housing affordability. The HPI is published by the Federal Housing Finance Agency (FHFA) using data supplied by Fannie Mae and Freddie Mac.

The HPI is based on transactions involving conventional and conforming mortgages - only on single-family properties - that have been purchased or securitized by Fannie Mae or Freddie Mac. It is a weighted, repeat-sales index, which means that it measures average price changes in repeat sales or refinancings on the same properties. A comprehensive HPI report is published every quarter, while a monthly report has been published from March 2008.

The HPI differs from the well-known S&P/Case-Shiller Home Price Indexes in a number of ways. For example, while the Case-Shiller indexes only use purchase prices, the all-transactions HPI also includes refinance appraisals.