Capitalism is a "blatant failure" when it comes to housing the poor, says Jacinda Ardern.

In the 37-year-old's first sit-down interview since becoming Prime Minister-elect, Ms Ardern said Kiwis are not "feeling the benefits of any form of posterity" and big changes were needed.

"Wages are not keeping up with inflation, the cost of housing is outstripping most people's reach," she told The Nation's Lisa Owen.

"What is the point of economic growth when we have some of the worst homelessness in the developed world?"

The Government she's formed with New Zealand First, with support from the Greens on confidence and supply, would be an "active" one when it came to plugging capitalism's holes.

"When you have a market economy, it all comes down to whether or not you acknowledge where the market has failed and where intervention is required. Has it failed our people in recent times? Yes. How can you claim you've been successful when you have growth roughly 3 percent, but you've got the worst homelessness in the developed world?"

Ms Ardern said her Government wouldn't measure economic success just on things like GDP.

"The measures for us have to change. We need to make sure we are looking at people's ability to actually have a meaningful life, an enjoyable life, where their work is enough to survive and support their families."

Asked directly if capitalism had failed low-income Kiwis, Ms Ardern was unequivocal.

"If you have hundreds of thousands of children living in homes without enough to survive, that's a blatant failure. What else could you describe it as?"

The Government's first move would be to introduce its families package, followed by writing child poverty reduction targets into law.

"Every year there will be a report, as part of the Public Finance Act, on how much progress we have made."

The minimum wage will also go up in Labour's first 100 days - first to Labour's promised $16.50, then beyond. NZ First's policy is to raise it to $20 an hour.

"It was a strong focus for Mr Peters, it was a strong focus for us. You'll see change in that area," said Ms Ardern.

"We have to make sure we balance the need to see that wage increase whilst at the same time ensure that we give enough notice so we can ensure the cushioning for those who are paying those wages. $16.50 is our first step. We'll look to move beyond that over time."

Asked if she accepted an interventionist economic policy could be described as "nationalistic", Ms Ardern didn't disagree.

"If that's the way you want to describe a Government that's going to be active and focused on making sure we have jobs in our regions, that we have infrastructure that's well-supported and that we're growing our economy by ensuring that we are investing in our people, then that might be the way you describe it.

"I describe it as a proactive Government, one that's focused on people."

The new Government will be sworn in on Thursday morning at Government House, after ministerial positions are confirmed.

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