• Liam Martin is a lecturer with Victoria University's Institute of Criminology with an expertise in prisons.
In the lead-up to the election, Kelvin Davis announced that Labour will work to reduce the prison population by 30 per cent. The party inherits quite different priorities in government.
There are plans to build an enormous prison complex in Waikato, part of a sweeping $2.5 billion package to expand prison capacity. It is not too late for Labour to scrap this plan in favour of the vision they bring with them to office. But with construction set to begin next year, it would have to happen quickly.
If prisons worked there would be no need to build another one. Consider the network of new prisons that already crisscross New Zealand: Ngawha prison opened in the Far North in 2005, Auckland Women's in 2006, Spring Hill and Otago prisons in 2007, the remand prison at Mount Eden in 2011, and two years ago, a partnership with multinational Serco on old industrial land in South Auckland.
We could be using these resources to build homes for our people. Yet in the past 20 years, the number of houses owned by the government has fallen from 70,000 to 63,000.
A Treasury official described the construction of Otago and Spring Hill prisons as the "equivalent of building two small towns". Imagine if these small towns were filled not with cages but with houses - affordable houses suitable for the most vulnerable New Zealanders. Does anyone believe the country is safer now because the choice was made for prisons instead?
The prison boom and housing crisis are twin problems that trap the same people. The most marginalised New Zealanders cycle between sleeping in cars and doorways and the cells of brand new prisons.
Many already know that we have among the highest rates of incarceration in the developed world. But on homelessness we look even worse: here New Zealand is No 1, with more homeless people per capita than any country in the OECD - more than even the United States.
The plans for more prison building are doomed to failure. The new facility will stand alongside the existing prison at Waikeria deep in rural Waikato, 16km south of Te Awamutu. It is a site of social isolation that places prisoners far away from their families and other networks of support, severing relationships that provide the best hope for successful resettlement after release.
The resulting complex will not only be isolated but huge. Where Scandinavian prisons usually hold 50 to 100 prisoners, creating a culture of familiarity and close relationships between staff and inmates, Waikeria already holds 800 men. With the new facility it will be large enough for 3000 - far and away the biggest prison in New Zealand, almost triple the size of any other.
These are decisions made on the basis of cost. It is much cheaper to build a huge institution on Corrections-owned land in rural Waikato than small local prisons in cities.
They are also decisions that all but guarantee the need for more prisons down the road.
Labour's public target to reduce prison numbers is a first for a major political party. But talk is cheap when construction is set to begin on an enormous new prison.
When he was Finance Minister, Bill English famously called prisons a "fiscal and moral failure". As Prime Minister he approved massive investment in prison building. Now we see if Labour in government will be truer to their convictions.
• An earlier version of this article included a comparison of budgets for corrections and building and housing, but this was removed to reflect updated information about allocations in budget 2017/18.