Fiscal policy involves the use of levels of government spending and tax settings to influence aggregate demand in the economy.
"The question is: what do we care about? We have inflation down near zero, but that's not necessarily such a bad thing, we have price stability," he said.
"If we care about stimulus and we care about growth that's not something for central banks. It's something for other arms of government - pushing productivity which is particularly low, that's far more pressing if we care about growth and aggregate demand."
Changing a target now would potentially lead to confusion, he said.
Westpac acting chief economist Michael Gordon said he wanted to see a tighter focus on the inflation target, although he wasn't in favour of shifting from the 1 to 3 per cent range, or 2 per cent mid-point.
"Some people say inflation targeting is dead, if that's so then it's been killed with kindness," he said.
"There needs be tighter enforcement of it. The problem at the moment is the only option the Finance Minister or the Reserve Bank board has is the nuclear option of sacking the governor, and of course they don't want to do that, so it's just left to drift."