Frequently asked questions (FAQs)
How does the price index work and what methodology is followed?
We maintain property price and availability (stock) data dating back to 2006. However, we consider the data from 2011 onwards to be the most reliable and suitable for in-depth analysis. The analysis of this data is part of a long-term project that we have been continuously developing over the years, leveraging modern data storage, processing, and analytics methodologies, as well as automated workflows, with the aim of building an increasingly “intelligent” and robust system.
It should be noted that outlier values are automatically adjusted through systems we have developed for each individual geographic unit. Our database includes approximately 20,000 geographic areas across Greece, and adjustments are performed on a monthly basis for every type of search (sale or rental) and for each property category (residential, commercial, or land). As a result, approximately 120,000 different acceptable price ranges are calculated every month, by area and search type. These ranges may vary from month to month, even within the same neighborhood, as they are fully recalculated with the addition of new data.
This level of granularity and analytical depth enables automatic, monthly adjustments for every property type and neighborhood across Greece, something that would be inherently impossible to achieve with the same frequency and accuracy through manual review. Neighborhood-level analyses are subsequently aggregated at the municipal level, and grouped municipal analyses form the data presented on the publicly available Spitogatos Price Index (SPI) page, by broader geographic area.
The data we use is based on median values, with processing primarily carried out using median deviations, while also taking into account and cross-referencing mean values and standard deviations for each area. Our methodology is designed so that the historical performance of each area is incorporated into future calculations of average prices, supporting both normalization and accurate interpretation of newly added monthly data. In cases where results are not displayed, this indicates the absence of a statistically significant sample.
Spitogatos Price Index (SPI) data is updated on a monthly basis.
