Spain house price indices: IPV, IMIE and which is the most reliable

When you read that "house prices rose by X% in the last quarter", do you know which index they're talking about? The problem is that the different house price indices in Spain measure different things with different methods, and they can give divergent results for the same period. Here I explain them all.

The INE's IPV (house price index)

This is the government's official statistical house price index, published by the INE (Instituto Nacional de Estadística, Spain's national statistics office). It is calculated from real transaction data (sale deeds with a declared price) collected by notaries. It measures the change in the price of homes with similar characteristics between periods (a hedonic index). It is the most reliable for measuring the real change, because it uses actual transaction prices, not asking prices. It is published quarterly with a delay of 3-4 months.

TINSA's IMIE (Spanish property markets index)

It is published monthly by TINSA, the largest valuation company in Spain. It is based on completed valuations (mainly for mortgages), which makes it very close to the real market price. It reacts faster than the IPV and is published monthly. It tends to be slightly more conservative than the portals' indices.

The Idealista and Fotocasa indices

They are based on the asking prices advertised on their portals, not on real transactions. Because they reflect what sellers ask (not what deals close at), they tend to be 5-15% above the actual transaction price in normal markets. They are more useful for seeing the trend in supply and the psychology of sellers than for knowing the real price.

Which to use for each decision

For long-term trend analysis: the INE's IPV. For monthly tracking and a quick reaction: TINSA's IMIE. For asking prices and negotiation: Idealista/Fotocasa. For a mortgage and a valuation: the bank will use its own valuation company.

Up-to-date data by area: RadarPro integrates the main price indicators for each asset analysed. Also read the guide to statistical sources on the property market.