An 18-month high for inflation is not due to carbon tax, according to the latest figures.
TD Securities-Melbourne Institute's monthly inflation gauge rose by 0.6% in August, the biggest increase since March 2011.
The rise was blamed on increases in "volatile" items including fruits, vegetables and automotive fuel.
Interestingly, the carbon tax was not a significant factor, said head of Asia-Pacific research Annette Beacher.
“We do not identify any specific impact of the carbon tax spilling over into prices this month, with utility prices unchanged after the July spike.
"While fruit and vegetable prices rose strongly, it is difficult to extract if the carbon tax is a contributing factor,” she said.
The quarterly figures for September matched August's increase, with both headline and trimmed-mean inflation rising 0.6%.
Meanwhile, Beacher predicts RBA
will sit tight on the cash rate today, for a third consecutive month.
"Outsized mining investment for this current financial year has been confirmed, GDP growth remains robust, and the Governor has presented an upbeat view on the outlook for Australia for some time.
"A repeat of “monetary policy settings remain appropriate” is the sensible course for now ahead of what could be an eventful September for global central bank policy announcements,” she said.