Next Friday the 14th August 2009 the NZ Real Estate industry body, REINZ will launch a new initiative, as this will be the date the first “Monthly Housing Price Index” will be published.
The aim behind this new report is to take advantage of the data the Institute compiles each month….or as they say…
Monthly statistical information collated by the Real Estate Institute of New Zealand (REINZ) will be the basis of the REINZ Monthly Housing Price Index, an important new tool for analysing the housing market to be launched this month.
According to a Press Release issued today, they will offer ……
indexes for Auckland, Wellington and the rest of the North Island, Christchurch and the rest of the South Island. There will also be a REINZ Monthly Residential Section Price Index.
Its looking like Nelson / Tasman will be aggregated within the “Rest of South Island” at this stage.
The press release mentions that behind the scenes the REINZ has been working with the Reserve Bank of New Zealand for many months to develop a “stratified housing price measure.”
There’s a TVNZ article over here too, discussing the new report, but more from the Reserve Banks point of view.
UPDATE via Reserve Bank of NZ site…
How stratification works
* Dwelling sales from approximately 1800 New Zealand suburbs are ranked according to their median sales price over the relevant comparison period (currently January 2005 – June 2009).
* The suburbs are allocated into ten different groups (or strata). Suburbs accounting for 10 percent of the lowest sales by price are grouped into stratum 1; suburbs with 10 percent of the most expensive sales price are in stratum 10. The allocation of suburbs to each stratum is fixed over the comparison period.
* The number of sales and median sales prices in each stratum is used to obtain a sales-weighted median price. This puts more weight on suburbs where there are more sales while filtering out sales of very high or low priced properties, giving a more stable measure of price trends for the stratum.
* The sales-weighted median housing price in each stratum is averaged to produce a housing price measure from which the housing price index is derived.