It says something about this Government's sense of urgency on housing affordability that it has taken five years to develop a measure that is two years out of date.
The official index announced this week subtracts the cost of housing (buying or renting) from a renting household's income. It then compares the money left over to a national median figure in 2013, called the national affordability benchmark.
The current threshold is $662 per week for a one-person household, with an extra $331 for each adult and $199 for each child.
The latest available data for would-be buyers shows 81 per cent of households in New Zealand and 86 per cent in Auckland fell below this line in June 2015. Unaffordability for renters was 66 per cent nationally and 64 per cent in Auckland.
At first glance the index looks like a new way of telling us what we already know. The nation has a regular stream of house price data and two well-established housing affordability indexes from interest.co.nz and Massey University.