The formula is: (Price per square metre / GDP per capita)*100. The house price to income ratios published by the Global Property Guide are based on the Global Property Guides own proprietary in-house research, but we use the IMFs GDP per capita figures.

The house price to income ratio is the ratio of the cost of a typical upscale housing unit of 100 square metres, compared to the countrys GDP per capita. Normally this ratio will be much higher in low income countries than in high income countries.

European statistics. European house price and other economic statistics vary in quality. It is often a surprise to non-Europeans to discover that swathes of this rich, highly developed continent are not covered by good housing statistics.

Northern European countries have generally good house price time-series. In particular, all the Scandinavian countries generate excellent house price statistics. In the Baltics the situation is improving rapidly. Latvia generates an official annual house price time-series, and the realtor Latio publishes a monthly index. Lithuania has no official house price or rents time-series, but the firm Inreal publishes annual prices and rents for Vilnius for a few years. Estonia has high-quality housing statistics, generated by the Statistical Office of Estonia (SOE). Data on house prices, house sales and construction activities, as well as general economics statistics are all available from the SOE.

Central Europe is mixed. German house price statistics are weak. France has very good statistics, the Netherlands has good data, Belgium and Austria have acceptable data. Spain has made giant strides, Portugal is weaker.

Southern Europe tends to have weak statistical data. There is a particular lack of housing statistics in Italy, Greece, and Turkey (though Italy has some private, for-sale, data generators).

Statistics in Eastern Europe are weak. Efforts are being made to change this, for instance Bulgaria began publishing a house price time-series in 2006. Aside from this, the Czech Republic has an official index, and in Poland, REAS Konsulting produces a for-sale index.