The International Monetary Fund in the Fiscal Monitor it released last week estimates age-related spending by the Government, which includes health care as well as super, will rise by 5.4 per cent of gross domestic product by 2030.
That is a pretty material increase on its current operating spending - on everything - of 30 per cent of GDP.
It is a larger adjustment than the average for advanced economies (3.8 per cent of GDP) and more than twice that forecast for Australia (2.6 per cent). It reflects the fact that we rely unusually heavily on a pay-as-you-go taxpayer-funded pension for retirement income.
In round numbers, today's taxpayers support about a quarter of a pensioner each.
By 2030 it will be a third of a pensioner and by 2050 half of one.
Whoever the Labour Party chooses to lead it cannot change the laws of mathematics.
Little concedes the point but adds that "unless we are returned to power we can't change anything".
The reaction he encountered on the campaign trail to the policy of raising the eligibility age was resistance to the idea of having to work two more years.
And when many workers are casualised, financially precarious and living hand to mouth, the long-term soundness of the Government's finances does not cut a lot of ice with them.
Even David Parker, whom you might expect to be a staunch defender of the policy, when he threw his hat into the ring asked somewhat plaintively why Labour should be the only major party "carrying the cross" of fiscal responsibility on super and suggested a referendum on the issue.
Good question, wrong answer.
Superannuation is one area (climate policy is another) that cries out for stability and cross-party consensus. But instead of statesmanship we get Prime Minister John Key's fatuous and self-serving assurances that the status quo on entitlements to New Zealand Superannuation is affordable and won't change on his watch.
Of course it is affordable if your time horizon is short enough and you are indifferent to the opportunity cost in spending on other things that it crowds out.
And if you ignore the obvious problem that taxpayers of the future are not captives. They are not serfs forbidden to leave their village.
In a globalised world economy in which people are mobile and in which most developed countries are ageing faster than New Zealand and deliver much higher incomes, a she'll-be-right attitude towards the status quo is absurd.
Parker "suspects" voters would agree if the question was put to them in a referendum, without the cacophony of other issues that inevitably occurs in a general election.
After all, the Australians seem to have accepted without a murmur raising the age of entitlement for their state pension to 67.
But Australia's retirement income regime, where compulsory workplace super has been in place for a long time now, is quite different.
When a similar scheme, albeit its design was a rush job, was put to New Zealand voters in the 1990s it became a referendum on its proponent, Winston Peters, and was massively rejected by the electorate.
Similarly in the early 1970s, when baby boomers were starting to move into the workforce in strength and the third Labour Government proposed something like the Cullen Fund, Robert Muldoon's dancing cossacks and a promise to cut the age of eligibility to 60 won hands down with the electorate.
The potential chilling effect, if there were to be a similarly short-sighted and improvident verdict from the public again, could be very costly.
Progressively raising the age of eligibility, to reflect increasing longevity, only nibbles at the problem of funding New Zealand Superannuation long-term.
Other measures, like changing the indexation to an average of wage inflation and CPI inflation rather than wage inflation alone, are likely to be needed as well.
There are lots of options but the status quo should not be seen as one of them and - as with climate change - the longer we pretend it is, the more unpleasant the eventual adjustment will be.
On capital gains tax, the way to sell the policy would be something like this: we have an income tax and capital gains are income. The broader the tax base, the lower tax rates can be.
It would take years for the revenue from a CGT to build to a useful sum and by then the issue of fiscal drag - that stealth tax increase by which nominal pay rises push more and more of wage and salary earners' incomes into higher tax brackets - will need to be addressed.
A CGT should be presented as part of a tax package, a trade-off for adjustments to income tax rates and/or thresholds, an explicit answer to "What's in this for me?" Not as a cure for house price inflation or a means of rebalancing the economy by encouraging savings to flow towards investment in productive enterprise and away from speculation in the housing market. Even if it has those effects, people either don't care or are profiting from the distortion in the status quo.
This is not to say that Labour has no policy it could usefully jettison. My list would start with New Zealand Power.
We can only hope that Labour's leadership contest over the month ahead is a contest of ideas and not just a beauty pageant.
