Selected price indexes (SPI) provide monthly price changes for a selection of goods and services that New Zealand households purchase. Key facts: {chart} {table} Difference between the flow and stock measures of rent: The flow measure of rents captures rental price changes only for dwellings that have a new tenancy started in the reference month. It tends to be more volatile than the stock measure, which shows rental price changes across the whole rental population, including renters currently in tenancies. (full story)