NSW govt won't commit to axing stamp duty

The NSW government won't commit to abolishing stamp duty, despite modelling which revealed the move would boost economic growth by more than one per cent.

If the hefty tax was replaced by a broad-based land tax, gross state product would increase by about $5 billion and up to 10,000 jobs would be created, a KPMG report commissioned by the NSW Council of Social Service and the NSW Business Chamber has found.

Treasurer Gladys Berejiklian said the NSW government was open to reforming state taxes to make them more efficient and fair.

"But reform must occur holistically and in the context of any broader reform of federal-state relations," she said in a statement to AAP.

She said increasing housing supply would be the most effective way of tackling housing affordability.

"Under our policies, building approvals for new homes has reached its highest levels for more than four decades," Ms Berejiklian said on Tuesday.

"At the same time, we have delivered the vital infrastructure needed to support new housing."

But NCOSS CEO Tracy Howe said the KPMG modelling made it clear that stamp duty would improve housing affordability in the state.

"It would remove the disincentive for people to buy and sell property," she said.

"It would also place downward pressure on rents over time as investors seek less return on their investment to cover their costs."

The new call for property tax reform, which unites the NSW Business Chamber, NSW Council of Social Services and the NSW branch of the Australian Manufacturing Workers Union, comes a few days after the state government rejected a federal government proposal for states and territories to levy their own income tax.