The problem with the debate raging around superannuation tax concessions in Canberra is that politicians find it easier to argue about parts of the retirement incomes system rather than look at the big picture.

For this reason, when Prime Minister Tony Abbott tells voters that Opposition leader Bill Shorten wants to raid “your money”, many will be convinced.

And when Mr Shorten tells working families that their tax dollars are helping the wealthy to bequeath larger estates to their heirs, many will also be convinced.

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• Why Frydenberg is wrong about super tax
• Labor’s super tax a gift to the rich
• Chris Bowen’s Robin Hood act needs work

These are, of course, contradictory propositions. It can’t be true that the concessions I receive are “mine” while the extra tax dollars I have to pay to fund your concessions are also “mine”.

However, with Treasury modelling showing that around half of super tax concessions accrue to the top 20 per cent of income earners, the politics of Mr Shorten’s move to reduce tax concessions on super incomes above $75,000 is straightforward.

Labor knows that the least well-paid half of the population share only 20 per cent of the tax concessions in the federal budget, hence there’s little bravery in Labor’s Robin Hood policy.

The bigger picture, that neither side seems to want to address, is the complex relationship between pension payments, super tax concessions and the ability of retirees to self fund their twilight years.

The Coalition argues that super tax concessions are there to encourage people to save more for retirement – and given its attempt to slow the indexation of pensions in last year’s budget, it clearly thought that lower future pensions would be yet another incentive to make more concessional contributions to super.

But the problem, reflected in the disproportionate skewing of super tax concessions towards higher income groups, is that the higher one’s marginal tax rate, the greater the incentive to stash money away in super. That’s the reverse of what’s needed.

For example, if you are paying 45 cents in the dollar, the concessional rate on super contributions of 15 cents in the dollar knocks 30 cents off your tax bill for each dollar put away.

By contrast, if your top tax rate is 19 cents (currently levied on income between $18,201 and $37,000) you’re only saving four cents for each dollar put away for retirement.

Returning to that bigger picture, then, it is not wealthier groups who need to be encouraged to reach escape velocity to leave Planet Pension forever. It’s middle- and low-income earners who need encouraging.

Indeed, as the chart below highlights, when Paul Keating set up the super guarantee in 1991 it was assumed that the only way to ‘encourage’ lower-paid workers to pay for their own retirement was to make it mandatory. Mr Keating had his sights in the long-term set on a 15 per cent contribution rate.

What is intriguing about this chart is that it incorporates Labor’s planned increases in the super guarantee rate – from nine per cent to 12 per cent over a period of years – largely offsetting the current blow-out in tax concessions.

Towards the end of the Gillard/Rudd years, Labor raised the super guarantee to 9.25 per cent, with other increases set to bring the rate to 12 per cent in 2020.

The incoming Abbott government tried to pause the rate at 9.25 per cent for two years. However, Senate opposition forced it to raise the rate to 9.5 per cent last July and to then postpone the next rise to 2018. That would see the 12 per cent mark hit in 2023.

In the chart above, from modelling done by Treasury when Labor was still in power, the cost to the budget of lost taxes would rise as every worker was given higher tax concessions to reflect their higher super contributions. However that cost to the budget would stabilise from 2020 onwards.

Meanwhile, larger super balances would take more people off the full or part pensions, creating large budget savings – that’s the blue line at the top.

The net result of the cost and the saving, represented by the red line, is the super system doing what it was designed to do – reduce the burden of pensions on the federal budget over time.

Three years on, however, the debate is stuck on the ‘fairness’ of reducing tax concessions – or of not reducing them.

In fact, if the super guarantee schedule had been adhered to, it might be possible to argue that super tax concessions be left alone – though that would need to be backed up with robust modelling.

In the event, the schedule was paused, and politics being what it is, it could be slow to restart.

What’s really surprising is that Labor has failed to make a serious effort to highlight the negative impact on the budget of the Abbott-Hockey delay to raising the super guarantee.

Instead, Mr Shorten and Shadow Treasurer Chris Bowen have wriggled into their Robin Hood tights to take money off the wealthy – but not nearly enough to offset the pension cost blowouts in the budget.

In economic terms, it’s the big picture of the retirement incomes system that counts. In political terms, chest beating over whether it’s “your money” or “my money” is taking precedence over funding a dignified retirement for all Australians.