The International Monetary Fund has given its support to the Federal Government's planned resource super profits tax.

The deputy head of tax policy at the IMF Philip Daniel has told a tax conference in Sydney this morning the proposal is a worthwhile reform.

He says there are a number of benefits in the RSPT which could also be adopted in other countries.

"IMF staff welcome the RSPT proposal in principle. It shifts the whole Australian resource tax system strongly in the direction of neutrality," he said.

"It offers strengthening of Australian public finances over the long term, reduces risk of absolute loss for investors, while leaving a substantial share of resource profits in private hands."

The IMF also says there is no indication that the Federal Government's proposed RSPT would hurt Australia's economic prospects.

Mr Daniel says the argument that the tax would hurt Australia's competitiveness is overstated.

"The tax proposal doesn't show adverse effects on Australia's economic prospects either," he added.

"Consensus forecasts offer evidence that the outlook for business investment has in fact strengthened for Australia in recent months."

He says not enough focus has been given to the benefits the mining industry should gain through the Government's assumption of some of the project risk.

"The argument on tax competitiveness too tends to ignore the fact that the new proposals incorporate large risk bearing by Government - to the extent of 40 per cent of losses and more in the case of exploration," he explained.

"Few other jurisdictions seeking petroleum and mining investment are able to offer that."

However, a resources economist says the super profits tax proposal may not raise as much money as the Federal Government predicts.

Ben Smith is a visiting fellow at the Australian National University and says the retrospective application of existing projects would guarantee solid revenues, but only in the short-term.

"In the long run, the Government is going to earn 40 per cent on the average rate of return of mining and in the long run that's not guaranteed to be particularly high," he said.

"It could even be negative - that's unlikely but, you know, there are risks associated with it and the Government really needs to spend the revenue taking account of those long run factors."

However, he also says the mining industry's campaign has been misleading and potentially damaging.

"To tell people that the consequence of this tax is that all mining industry profits will be taxed at the rate of 56.8 per cent and that this is the highest tax rate in the world - which is a gross distortion of the actual consequences of the tax - is likely to make people think twice about whether they want to invest in mining in Australia, until they see that this is a gross distortion," he added.