What took hold of Nick Smith when he personally extrapolated some Motu estimates to dramatically claim that the Resource Management Act added $30 billion to housing costs and stopped 40,000 new houses in the past decade?
It's a stunning and memorable figure.
It certainly captivated reporters who read the $30 billion figure in the Environment Minister's speech announcing the shape of his RMA reforms and put it high up their news stories.
It also played into the issue du jour for this week: Housing.
Those stories about "Auckland making the world's top 10 list for housing unaffordability"; "The failure of the Government's Auckland Housing Accord to result in real progress"; and "Fund manager Brian Gaynor's prediction of a housing market correction".
They're the type of headlines and speculations that might tempt a politician into some extravagant blame-shifting of his own to deflect attention away from the reality that the National-led Government is not tackling the housing crisis with sufficient urgency and focus.
What Smith's conflation did was invite us to arrive at the conclusion that all would have been hunky-dory on the housing front if the RMA - or the way the Auckland Council in particular has interpreted it in the application to its own planning regulations and decisions - hadn't imposed far too many ridiculous constraints on developers.
That's because Smith's 40,000 figure conveniently lines up with the identified shortage of 39,000 new homes in the city.
But it is barking to imply that all those 40,000 houses would have been built during that past decade if the RMA requirements hadn't resulted in additional costs.
The housing environment is much more complex than that and Smith knows it.
There's the reality that banks constrained lending to property developers - residential and commercial - after the global financial crisis. That's because when the tide went out after the GFC and prior NZ recession, banks were over-exposed to too many developers with too much debt who couldn't deliver up buyers for their projects.
There are plenty of other factors, of course.
But the demand pressure wasn't as high in Auckland back then either.
New Zealanders were still flying the coop to Australia and further afield. The galloping trend of Chinese taking their part in the global housing market (alongside many international buyers) and buying residences in choice locales such as Auckland had yet to take off. Immigration had not kicked up either.
So it's fatuous of Smith to place too much reliance on his back-of-the-envelope calculations.
As you would expect, there are some gems in the Motu report - Impacts of Planning Rules, Regulations, Uncertainty and Delay on Residential Property Development - which was commissioned by the Treasury and the Ministry of Business, Innovation and Economic Development.
The Motu analysts talked to 16 developers about the hurdles they faced on a total of 21 projects in Auckland. There have been bureaucratic costs; projects that didn't proceed; additional costs imposed because of council requirements that apartments have balconies, minimum floor plates and room heights and so forth.
RMA changes will assist the council to ensure land is freed up on the outskirts of Auckland and to pave the way for increased intensification in inner-city suburbs.
But there also needs to be political will at Auckland level to push the changes through.
That's why Smith's headline grabbing is so annoying.
Having served with Motu's Arthur Grimes - a former Reserve Bank Governor - on an economic development advisory group for the previous Auckland City Council I have some respect for how he works. Which is why I read the Motu report twice to find the sourcing for the $30 billion additional housing costs imposed by the RMA over the past decade and how it had reduced housing supply by 40,000 homes over that period.
It wasn't there.
Smith's press secretary yesterday said: "The minister did [find it], you'll come up with the same figures if you [do] the calculation yourself."
Actually, I wouldn't make that kind of invalid calculation.
Nor would I place too much reliance on the saving the developers reckon could be achieved by relaxing the planning rules.
The potential cost reductions outlined in the Motu analysis will have little impact during a housing bubble.
That's the reality Smith and his other ministerial colleagues have not fronted up. Relying on a political syllogism doesn't cut it when people want affordable homes in Auckland.