But he attributed 70 per cent of the Budget 2022 operating allowance increase to cost pressures.
Just like the rest of us, the Government has to spend more to maintain the status quo, before putting money towards improvements or "nice-to-haves".
In fact, the Treasury estimates departments' baseline expenses will need to increase by $3.5b in next year's Budget to simply maintain the existing level of services. That's categorically a lot.
The Treasury warned the Government would either need to increase taxes, reprioritise spending or increase the Budget 2023 operating allowance to absorb these costs, while funding new initiatives already committed to.
Add to this the pressure on the Government to spend money to ease the pain of inflation, and the costs keep tracking up.
Robertson committed to spending $814 million to pay those who earn less than $70,000 a year, who aren't eligible for the Winter Energy Payment, $27 a week for three months.
He put $235m towards extending the current three-month fuel tax cut by two months. He also allocated $132m towards extending the halving of transport fares by another two months, and introducing a new ongoing 50 per cent fare discount for Community Services cardholders.
While these measures will give Robertson a defence in the face of accusations from his political opponents that he's "neglecting the squeezed middle", the mostly temporary tidbits of support will fade long before inflation does.
The Treasury expects annual inflation, at 6.9 per cent in the March quarter, will ease to 5.2 per cent by June 2023 and won't get back to the Reserve Bank's target range of 1 to 3 per cent until 2025.
Furthermore, the support will fade before next year's general election, putting a major question mark over whether Robertson will feel compelled to extend the support and/or put more money towards new inflation painkillers in Budget 2023.
He will need to avoid the political temptation to prescribe painkillers to those who don't really need them, as this would only exacerbate the problem.
Further to facing higher costs soothing the sting of inflation, and simply maintaining the status quo, the Government faces rising interest rates on the large amount of debt it's issued in this Covid-19 era.
The Treasury expects core Crown finance costs to increase from $1.9b in 2021 to $4.6b by 2026.
There is a mitigating factor for the Government's books: Inflation puts upward pressure on wages and lifts the cost of goods and services, which increases the GST and income tax take.
Nonetheless, the Treasury summarised the downside risk associated with inflation quite simply: "If inflation pressures prove more persistent, the medium-term implications for economic activity in New Zealand could be significant."
The Treasury doesn't use words like "significant" lightly.
So, inflation will continue to hog the mic and cause a ruckus in future Budgets, until it's booted out of the party ... which puts the focus on the bouncer or inflation police – the Reserve Bank.
The central bank is expected to hike the official cash rate by 50 points to 2 per cent on Wednesday.
Fielding critical questions on inflation, the Reserve Bank will likely point to the fact it started taking action, hiking interest rates ahead of most of its counterparts around the world.
It'll also note it can't control key sources of inflation – the war in Ukraine, which is putting upward pressure on oil prices, and Covid-19, which is disrupting supply chains, restricting the movement of people and exacerbating capacity constraints.
But the Reserve Bank should commit to undertaking a proper post-mortem of its response to Covid-19.
It might conclude that providing as much stimulus, for as long as it did, was better than risking higher unemployment.
But had the Reserve Bank, with the support of the Government, not relied so heavily on pumping up house prices to save the economy, the Government might not be under as much pressure to support low-income households grappling with high rents.
Furthermore, the Reserve Bank wouldn't have to risk killing the economy in its attempt to kill inflation.
Because New Zealand households have so much more mortgage debt, they're incredibly sensitive to interest rate changes. Rises will bite some people particularly hard, again, pressuring the Government to provide relief.
Inflation will characterise Budget 2023, as it has underpinned Budget 2022.
