Using household-level data from the Statistics New Zealand Integrated Data Infrastructure (IDI), The Housing Affordability Measure is a new approach to measuring housing affordability. This measure provides a picture of shifts in affordability, broken down by region and territorial authority (and by ward in Auckland).
In August 2012, as part of a review of the Official Statistics System, Cabinet agreed that work should be undertaken towards the creation of a Tier 1 official statistic on housing affordability. The Housing Affordability Measure (HAM) is an experimental statistical series that measures household income after paying for housing costs for two subsets of the population: potential first home buyers population and renters.
Affordability is calculated by using data from Statistics New Zealand’s Integrated Data Infrastructure to measure income at the household level. Housing costs – the rent lodged on tenancy bond forms for renters and mortgage payments, rates and insurance for potential first home buyers – are then subtracted. The remaining household income is then adjusted to reflect the fact that larger households generally need larger incomes.
As the lead government agency on housing policy, the Ministry of Business, Innovation and Employment (MBIE) assumed the responsibility for developing these two indicators. The HAM’s first set of results, up to June 2015, presents key findings about housing affordability trends at a national level and for the three most populous regions of New Zealand.