While that pesky surplus is proving rather capricious, this year’s budget shows tentative progress towards fiscal objectives.

The Initiative’s 2014 report Guarding the Public Purse, argued that greater productivity growth, competition and spending restraint were essential to achieving longer-term fiscal sustainability. And, to avoid a projected debt spiral, the annual primary operating balance between now and 2060 may well need to average 1.7 percent of GDP.

Treasury’s updated fiscal model projects an encouraging average annual surplus of 2.5 percent of GDP between now and 2029 on current policies. If achieved, a debt spiral becomes far less likely.

But how plausible is this? It involves reducing core Crown expenses from 30.5 percent of GDP to 26.7 percent of GDP by 2029, while revenues rise marginally faster than GDP thanks to the cheeky effects of fiscal drag.

Stuffing the promised fiscal cushion will be no easy task. How future governments will actually safeguard fiscal pressures from the (geriatric) demographic bulge is, alas, left to our imagination.