While, typically of this government, Friday’s release of Treasury modelling on the impact on households of various carbon prices was unaccompanied by any apparent plan for explaining it, it provides some data around which to contextualise the effect of introducing a price on carbon.

Treasury modelled the impact of eight scenarios — carbon prices of $10, $20, $30 and $40 a tonne of CO2-equivalent, with a fuel rebate (as per the CPRS) and without. The impacts on households therefore varied widely. A $10 carbon price with a fuel rebate would be barely noticeable, costing $200 a year. The $40 carbon price, without any fuel concession, costs $1150 a year.

The $40 price is the best one for comparisons, because even if Labor and the Greens opt for an initial low price, it’s going to have to rise significantly if we’re to have any chance of meeting anything higher than the government’s paltry 5% 2020 emissions reduction target. With a fuel rebate, almost certain to be included in the carbon price scheme, that’s $15.60 a week, or $811 a year, including $286 in increased electricity costs.

As you’ll recall, Tony Abbott and Greg Hunt went through a phase of claiming that a $30 — not $40 — price on carbon would produce increased electricity costs of $1110 a year. This year, they quietly abandoned the $1100 figure and reverted to saying it would lift electricity prices by $300.

They’re in the ballpark — but for a $40 carbon price, not a $30 carbon price, which would raise electricity prices by less than $220 a year, even without the fuel rebate. Well done to John Quiggin, who suggested a $30 price would produce an electricity price rise of $200 a year back in early February when he demonstrated what rubbish Hunt was talking.

How do all these stack up against other items in the household budget?

For starters, it’s far less than the GST. If a carbon price is a great big new tax, Tony Abbott must’ve had an absolute conniption contemplating the GST back in 2000. According to last year’s Budget figures, in 2012 we’ll pay about $51 billion in GST. That’s on average — and remember we’re only ever dealing here with a mythical “average household” — just over $6000 a year, or $116 a week. As Treasury noted in another document released last week, the GST had about 3.5 times the cost impact that a $20 carbon price would have.

The Renewable Energy Target — the only climate change policy on which there is agreement right across the political parties — in its latest form increases electricity prices by $41 a year, according to Treasury. Ross Garnaut has argued that the RET should be dumped as soon as a carbon price is implemented. Garnaut also suggested continuing state ownership of electricity generators in NSW and Queensland was driving up network investment by much faster rates than necessary, although this wasn’t costed. But network investment costs dwarf the role the of the RET in rising power bills.

Once you start playing this game, there’s all sorts of perspectives you can bring to the cost of a carbon price. The ABS’s Household Expenditure Survey is now a little long in the tooth — the most recent one was 2003-04 — but it gives a sense of where a $15.60 a week carbon price bill would fit. It’s well below what the average household spends on alcohol, in current prices about $30 a week. It’s just over what the average household spent in 2003-04 on tobacco, but you’d imagine that has fallen significantly since then. It’s about twice what the average household spends on gambling, but well below the $22 a week we spent on average on toiletries and cosmetics. It’s about half what we spend on fast food every week and about two-thirds what we spend eating out, and a couple of dollars a week more than what we spend on sweets and chocolate.

According to figures quoted by AMP’s Shane Oliver, every $10 rise in the price of oil adds eight cents a litre to the cost of petrol locally, translating into an extra $3.60 a week for the average household

Alternatively, you can cast it in terms of other government policies. The Productivity Commission found we spend about $1.3 billion a year propping up 50,000-odd jobs in the automotive manufacturing sector, which amounts to $151 per household of taxes. The private health insurance rebate costs, in its recently revised form, $3.5 billion a year, or $437 per household in taxes. A levy to fund the national disability insurance scheme proposed in early February by the PC would cost just under $600 per household a year.

Or there’s Tony Abbott’s paid parental leave scheme, funded by a levy that, if passed through by businesses (the same way a carbon price would be), would have cost households on average $390 a year.

Lower-income households would plainly find it more difficult to find a lazy $800 a year than others. There’s a strong case for compensation for such households, given the incentive isn’t to raise revenue but change behaviour. But, based on these numbers, as household incomes rise, the case for compensation falls away. Middle income households face a non-trivial but hardly significant rise in household costs from even a $40 carbon price. The policy question is, is using carbon price revenue to compensate middle-income households the most effective use of that money, or would it be better directed at minimising the first-mover disadvantages facing investors  in renewables technologies, or even at compensating industry rather than households?

Such a question isn’t likely to be answered. The case for compensation of middle-income households is mostly political, and therefore entirely compelling for politicians.