House price index

A House Price Index (HPI) measures the price of houses.

USA
In the USA, main HPI measures the cost of single-family houses and is published by the Office of Federal Housing Enterprise Oversight.

The HPI is measured monthly and tracks repeat sales of houses using a modified version of the weighted-repeat sales methodology proposed by Karl Case and Robert Shiller. This means that, to a large extent, it is able to adjust for the quality of the homes sold, unlike simple averages.

The HPI was developed in conjunction with OFHEO's responsibilities as a regulator of Fannie Mae and Freddie Mac. It is used to measure the adequacy of their capital against the value of their assets, which are primarily home mortgages.