The Reserve Bank could increase interest rates eight times in the next two years, former board member John Edwards said.

The RBA is probably already considering a program of rate increases given its forecasts for inflation returning to target and economic growth to accelerate to 3 per cent against a stronger global backdrop, Edwards said in a column on the website of the Lowy Institute for International Policy, where he is a non-resident fellow.

Theorising that the long-term cash rate is about 3.5 per cent -- lower than the 5.2 per cent average over the past two decades -- and the RBA wants to start tightening in 2018 and reach its goal within two years, that would require four quarter-point increases each year, he said. Rates have been on hold at 1.5 per cent since last August.

"It seems to me that something like eight quarter percentage point tightenings over 2018 and 2019 are distinctly possible, if the RBA's economic forecasts prove correct," said Edwards, who was on the bank's board until July last year.