If Malcolm Turnbull's promised tax cuts ever eventuate, we can be sure they'll be justified in the name of redressing terrible "bracket creep". But there are few aspects of taxation that involve more deception.
Treasury has been overselling the bracket creep story since the arrival of the Abbott government, while the Turnbull government has been exaggerating how much of it there's likely to be, so as to prop up its claim it's still on track to return the budget to surplus in 2020-21.
Every politician with their head screwed on loves bracket creep. When pressed, however, all profess to think it a bad thing. The punters think they disapprove of it, but their "revealed preference", as economists say (what they do rather than what they say), tells us they prefer it to the alternative.
It's only commentators like me who are free to say openly that, in this imperfect world, bracket creep's a jolly good thing and there ought always to be a fair bit of it.
Bracket creep occurs when a taxpayer's income increases by any amount for any reason. That's because we have a progressive income tax scale – one where successive slices of income are taxed at higher rates in the dollar – that's fixed in nominal terms.
Sometimes the creep happens because the increase in income lifts the last part of someone's income into a higher tax bracket, but it occurs even if this isn't the case. That's because the higher proportion of their income that's taxed at their highest ("marginal") tax rate increases the average rate of tax they're paying on the whole of their income.
If politicians really disapproved of bracket creep they could eliminate it by indexing the tax scale's bracket limits on July 1 each year in line with the rate of inflation in the previous financial year.
If you wanted to allow only for the effect of inflation, you'd index the brackets to the consumer price index. If you were a true believer in Smaller Government, who thought it a crime for a person's rising real income to raise their average rate of tax, you'd index it to average weekly earnings.
That no government has indexed the tax scale in this way since Malcolm Fraser's abortive experiment with it in the late 1970s is all the proof you need that, whatever they say, politicians of both colours quite like bracket creep. Same goes for Treasury.
The pollies' preference is to let it rip, but then make big guys of themselves by giving some of it back about once every three years, just before or just after an election. Only during the first half of the resources boom, when their coffers were (temporarily) overflowing, did John Howard and Peter Costello depart from this approach.
I believe in bracket creep because it's always played a vital role in helping to balance the budget. It's part of the implicit contract between governors and the governed, who want ever-growing government spending, but don't like explicit tax increases, particularly new taxes.
Their unspoken message to governments is: you find a way to pay for the spending we want, just don't wave it in front of our faces. Bracket creep is the tried and true way of squaring this circle, with limited objection from taxpayers.
What few people seem to realise at present, however, is that we've had precious little bracket creep for the past four years because inflation has been unusually low, and wages have barely kept up with it.
Limited bracket creep is the greatest single reason the Coalition government has had so little success in returning the budget to surplus. The government's persistent over-estimation of the bracket creep that will come its way is the main reason it has kept failing to reduce the deficit as forecast.
Yet throughout this government's term, official estimates of the huge extent of future bracket creep have been published, seemingly making the case for big tax cuts. The latest, issued last month by the Parliamentary Budget Office, were reported as though they were established (and scandalous) fact.
In truth, they were mere projections, based on this year's budget projections that wage growth will accelerate to 3.75 per cent a year over the next three years – projections that have been pilloried as wildly optimistic.
I'll let you into a secret unknown to the innumerate end of the media: if your big economic problem is exceptionally weak wage growth, one problem you don't need to worry about is excessive bracket creep. Nor is there any urgent case for tax cuts.
