Under the proposal, a minimum percentage floor of GST revenue would be gradually introduced, increasing WA's share to make up for lower iron ore prices cutting the amount the state collects in mining royalties.

Spending on construction in Western Australia has been falling for several years and is forecast to continue. Perth house prices have softened, and the WA Government's spending of about $400 million on transport is nothing compared to the private sector's easing on investment in the wake of China's slowdown.

Rather than squabbling over tax, it would be more constructive if premiers, chief ministers and the Prime Minister worked together on all states and territories challenges.

Instead, Premier Colin Barnett, who is facing a tough election, is blaming much of the west's economic woes on an unfair GST distributions. His government complains of revenue losses from royalties and taxes across the board and accuses the Grants Commission of unfairness.

But it is the Grants Commission's role to ensure states have the means to deliver the same level of services to Australians regardless of where they live. The commission is right to factor in the West's collection of massive royalties from iron ore, an endowment that belongs to all Australians.

Mr Barnett wants a 75c in the dollar floor for all states. Mr Turnbull has not committed to a figure. The Prime Minister said setting a floor below which a state's share of the GST could not fall meant no other state would be disadvantaged based on their projected GST share.

But if one state is advantaged, other states and territories must make up the shortfall. The Commonwealth is not likely to step in with more money.

ACT Chief Minister Andrew Barr says the territory can ill afford to be generous. Its capacity to raise revenue in comparison to other states is limited because its major employer, the federal government, does not pay payroll tax.

Mr Barr says that's why a fundamental principle of the federation is Canberrans are compensated for this through the distribution of GST.

Economist and Tasmanian Saul Eastlake says Western Australia's persistent bleating reminds him of a pensioner who has won the lottery, then started complaining about losing the pension.

Mr Eslake said when the system was working in WA's favour, while commodity prices were rising, the State Government spent the lot. Spending per head of population rose by 5.9 per cent per annum.

At the height of the mining boom Canberra's skyline was filled with cranes as a construction boom grew on the back of revenue flowing from the west. But when the boom was over Canberra down sized sharply, weathering a property downturn and shedding public service jobs. Western Australia must learn to live with the post-mining downturn too.