When Tony Abbott took office federal tax as a proportion of GDP was 21.3 per cent. Next year's budget surplus, the first in a decade, will be built upon a tax-to-GDP ratio of 23.3 per cent.

That increase, that 2 percentage point lift in the national tax take, is the biggest since the administration of Gough Whitlam. It is the largest of any Coalition government in records going back to the days when John Gorton was prime minister and Les Bury his treasurer.

The lift in the tax take includes the planned changes to the low and middle income tax offset that should finally find its way into the pockets of Australian employees some time over the next 4 or 5 months.

This increase in the tax take is occurring on the back of stellar jobs growth and a recovery in corporate taxes - particularly from our iron ore miners who are enjoying a moment in the sun on the back of human disaster in Brazil.

But the Reserve Bank of Australia is also noticing something else. Taxes on households are growing faster than their incomes.

RBA governor Philip Lowe, in the speech where he signalled the bank board would take official interest rates to a fresh all-time low when it next meets, made more than one point about the interaction of tax and wages.

Dr Lowe noted that while household income had lifed by 3.25 per cent over the past year, tax paid by the same households had climbed by 10 per cent. "That is a big difference and it is unusual," he said.

He then offered a view on what has been going on. "One hypothesis is the tax office has got better at compliance," he said.

"The changes to the rules about expenses for investment properties that the government introduced in the budget a year or so ago, and the electronic matching that the tax office now does, and the ability of us all to do tax online."

That's tax growing at 10 per cent at a time when wages for most Australians are stuck in first gear, house prices have fallen and a record number of people are taking on a second job to cover their day-to-day expenses.

Dr Lowe didn't mention other changes, such as the extension of GST to online purchases from overseas suppliers, or even the crackdown on Centrelink payments that ultimately became the "robo-debt" fiasco, that have crimped the spending dreams of households.

His remarks can't be repudiated by the government. The truth is evident in the budget and the lift in the total tax take. Without total tax increasing, there is no budget surplus.

Labor can't have a go, either. It may have run into bigger troubles with the plans of Bill Shorten and Chris Bowen to take the total tax even higher, to 24.1 per cent, on the back of changes to negative gearing, capital gains tax and discretionary trusts.

Dr Lowe and the RBA reckons that household tax growing faster than household income is temporary, betting that it will come to an end.

The RBA has also been predicting for more than six years an imminent increase in wages, so perhaps a grain of salt needs to be taken alongside this prognostication.

What can't be ignored is another element to Dr Lowe's address. Sitting on the shelves of policy makers in Canberra, Sydney and Melbourne is a report by the Productivity Commission entitled Shifting the Dial.

Delivered to then treasurer Scott Morrison in August 2017, this page-turner was effectively a "how-to manual for boosting efficiency across the economy, driving our taxpayer dollars further and delivering a tangible benefit to ordinary Australians and businesses.

From forcing governments to properly vet a plan before promising big dollars (hello $4 billion on the Melbourne-Geelong very fast train) to robot dispensing of pharmaceuticals, this report advocated plenty of ideas worth considering. But almost two years on, it's collecting dust.

Dr Lowe pointed out that dealing with competition has to be on the nation's agenda. "One of the things that makes firms seek out new ideas, invest in new technologies, employ people is the fear of competition. So competition policy can, in fact, be a promoter of economic growth. I think it's worth looking at that again."

A government looking seriously at change? That would be worthy of a mention in the Guinness book of records.