The convenient distinction between good and bad debt means that, suddenly, everyone in the Coalition can now happily talk up the benefits of big time, public sector infrastructure spending along with the dividends and benefits that flow from this.
This may be true. But, of course, it all comes down to project selection and the economic rationale – as opposed to the political rationale - for putting up the money for particular projects.
Certainly, a lot more infrastructure funding to ease urban congestion and traffic in Australia's fast-growing major cities – either via better road networks or better public transport options – would be economically productive as well as politically popular.
But it's more difficult to measure the economic benefits of the first two major projects about to get the budget tick of approval - a second Sydney airport and an inland rail link between Sydney and Melbourne.
Not that there's been a rush until now to get actual progress on delivering Western Sydney airport at Badgerys Creek. Count the decades this has been talked about - only to be delayed indefinitely. The Turnbull government has finally changed that equation, along with the steady expansion of Sydney westwards making it more feasible to open another airport 50 kilometres west of the CBD.
But it's clear from the constant talk of the jobs and opportunities the new airport will create, that the government's impetus is also due to the need to be seen to be turning sods and talking up jobs in Western Sydney in time for the next election.
And although the Coalition has been careful to follow the letter of the 2002 sales agreement giving Sydney Airport right of first refusal on a second airport, the Coalition appears to have become belatedly keen on ensuring competition of ownership. Late last year, it abruptly withdrew the sort of financial support Sydney Airport had been expecting, leading to the board's decision this week not to proceed with the proposals.
But the timing of the next election, its commitment to have a new airport operating by 2026 and the need for an infrastructure budget to sell meant the government needed urgent action. That translated into a willingness to take over the building of the project itself, in veritable big government style.
The idea is that Badgerys Creek will be eventually sold to the private sector for a profit so that it doesn't have to be put into the "bad debt" budget figures in the meantime…and, of course, in this government's lifetime.
Yet the real airport capacity and productivity constraint in Sydney at the moment - and for many years to come - is really more to do with the artificial limitations on the operations of Kingsford Smith due to the "noise" issue also dating back decades.
The result is an extremely strict night-time curfew and no more than 80 flights in or out over any one-hour period, with the hour reset every 15 minutes. There's to be no change to that inflexibility.
At the same time, regional aircraft traffic takes up a lot of the available slots and generates less revenue than international flights, making moving them an obvious target to be shifted to a new but less convenient airport.
That's one of the political trade-offs that meant Deputy Prime Minister Barnaby Joyce was able to insist on simultaneous government backing for 1500 kilometres worth of an inland freight rail link between Melbourne and Brisbane. This is another project championed by generations of politicians but especially the Nationals.
Despite the enthusiasm for this project in country electorates, the long-term economic benefits are more dubious. It's not just that it's not expected to generate enough revenue over the next 50 years to cover its full cost, if capital costs are included.
It's also about the assumptions. How much freight really needs to go between Melbourne and Brisbane by rail within 24 hours, for example? Shipping has become an absurdly expensive alternative given the stranglehold of the Maritime Union of Australia on coastal shipping and the docks but it might make more sense economically to challenge that balance of power.
And while there's no doubt a lot of NSW grain that currently goes by truck could and should instead go by rail instead, it would be a much quicker, cheaper and more efficient option to just upgrade the NSW rail network. That would radically increase the efficiency of taking the grain to NSW ports for export even if better, longer rail sidings don't have the same wow factor as a brand new rail line
The other main economic driver is for coal haulage. On present trends, relying on strong growth of coal export volume for decades to come seems a risky assumption.
Infrastructure Australia said last year its analysis showed "evidence of a long-term stream of benefits to potential users of the project, users of alternative infrastructure and the broader economy" but pointed to a number of risks.
"Factors such as a decrease in demand for Australia's coal exports, weak oil prices, reduced demand for interstate freight, and upgrades to the Newell Highway, could adversely impact the economic case for Inland Rail," it found.
None of that sense of caution is likely to stop the government's determination to press ahead with its newfound enthusiasm for borrowing to fund "good infrastructure".
But it demonstrates this is not a risk-free option for the government and ultimately for the economy and taxpayers if the right choices are not made for the right reasons.
Treasurer Scott Morrison, Urban Infrastructure Minister Paul Fletcher and Assistant Minister Angus Taylor will all be closely involved in those choices but also in fending off the inevitable political desire for instant access to a new pot of "free" money.
