The quality adjustment for the IMPI takes place as a first step by means of a stratification according to the variables resp. to a property’s characteristics. I.e. for the calculation of the index the transaction data are divided by property type and commune type. In a second step, the FSO calculates out the qualitative differences between the properties traded in the previous quarter and the properties sold in the current quarter. For this purpose the FSO uses a hedonic model that it developed for this purpose.
