"My argument would be that we already have, from a fiscal point of view, tried to get ahead of the curve," he says.
"When we sat down to put together the Budget in May we significantly increased our proposed new operating spending and our new capital spending and brought that forward as well."
"So $3.8 billion of operating per annum and $10 billion of capital spending from four-year rolling allowance."
"That was our attempt to get ahead of the curve both because we saw some long-term need and also because we could see what was happening in the global economy."
Sitting down with the Herald this week, after speaking to a select crowd of finance industry leaders for Bloomberg News event, Robertson was keen to try and cut through the pessimism which has dominated forecasts this year.
"I do think its important we don't talk ourselves into a kind of winter gloom. I'm very optimistic about the New Zealand economy and I'm confident in the fundamentals."
He says he's keenly aware of the trade war fall-out and slowing global growth.
"As policy makers we have to look ahead and prepare ourselves for a situation that might occur. But we're not there yet."
Robertson acknowledges that one of the issues for policy makers - both on the monetary and fiscal side - is that attempting to get ahead of the curve can create an impression that things are worse than they are.
"We do have low public debt, we have surpluses out over the next four years, we have unemployment at an 11-year low. There's still strong growth in the economy it's just not at the levels we might have seen at recent years."
The prospect of negative interest rates and other unorthodox monetary policy tools have captured the public's imagination this year.
Despite being regularly asked to, Robertson remains cautious of straying into the Reserve Bank's territory and undermining its independence.
"Adrian Orr [the Reserve Bank Governor] said we live in very very very interesting times and I accept that we do," he says.
"For New Zealand, we're already in uncharted territory when it comes to monetary policy, with an OCR at 1 per cent."
On negative rates, he notes that there is a precedent for them in several countries now.
"The good news for New Zealand is that we're some distance away from that. Even that 1 per cent gives us a bigger buffer than other countries."
"I can't influence the Governor's decisions in that regard beyond the fact that we have a fiscal policy that is expansionary," Robertson says.
"That's been recognised by the monetary policy committee. They actually said that in their commentary: that in the first part of next year they see government spending playing a role in lifting the economy.
Reserve Bank Governor Adrian Orr has cut the OCR and warned negative rates are possible in New Zealand.
Photo / NZ Herald
"That's the part I've got to play and that's the part I'll focus on."
Okay, but what if things do get worse? It wouldn't be a stretch to spend up larger in an election year, I suggest.
"I'm not a big fan of election year Budgets," Robertson says.
"We said in our first year we wanted to rebuild some of the social foundations that we felt had been undermined.
"Clearly there has been a deterioration in the global economy – even from May when we did the Budget," he says.
"The Budget responsibility rules have always had that ability to be varied in the event of a significant global shock. But I remain confident about the fundamentals and our ability to withstand the kind of cycle we're in."
Robertson says he hopes to stay on a consistent path that builds progressively to address long-term spending challenges - in areas like infrastructure and mental health.
"I in no way apologise for trying to tackle these big, long-term issues and it will take some time to get on top of them."
Meanwhile, the Government looks set to face an opposition prepared to give the economy a fuel injection with tax cuts and spending on new roads.
"The Opposition is going to have to explain to New Zealand how they plan to pay for their promises," he says. "If they keep promising to spend more and to cut taxes that doesn't add up."
While he doesn't quite rule anything out, it seems unlikely Robertson would consider tax cuts even if emergency stimulus was needed.
Boosting infrastructure spending seems more likely.
Robertson points out the Government already has $17 billion of transport spending rolling out over four years.
There's big programme of building new schools and health infrastructure underway.
A new school under construction at Oturu. Photo / Northern Advocate
And new roads aren't off the table, he says.
"We've reordered the priorities. But there are number of large roading projects coming down the line as well. They are still there.
"We're keeping a close eye on the situation in the world," he says.
"When most people think about what should be part of stimulus they think of things that lift productivity and deliver long-term benefits. There's also the ability to do short-term things.
"But lets give the Budget that's passed in May a chance to work as well."
