The article explores different methods for comparing consumer price indexes and purchasing power parities across regions and countries. It also discusses creating price indexes when expenditure data is missing and analyzing price differences within a country. The researchers found that spatially correlated error structures can affect the accuracy of price index extrapolation. Additionally, they examined price dispersion in products like pasta and the measurement of non-market services. The study also looked at total factor productivity and purchasing power transfers in the Italian economy. Overall, the research highlights the importance of accurate price indexes in understanding economic trends and making informed decisions in financial markets.