Axing negative gearing would lift home ownership to as much as 72.2 per cent of households, cut home prices by just 1.2 per cent and lift rents "only marginally", a study shown to the Reserve Bank of Australia has found.
Preliminary results from the economic modelling exercise, believed to be the first of its kind in Australia, were presented to a RBA workshop last month and released on Friday.
Melbourne University researchers Yunho Cho, Shuyun May Li and Lawrence Uren conclude that eliminating negative gearing entirely would lead to an overall welfare gain of 1.5 per cent of GDP, making three quarters of the population better off.
The figure compares to a Treasury prediction of welfare gain of 1.2 per cent from Turnbull government's plan to cut the company tax rate.
Speaking after the release of the paper, Dr Uren stressed the research was incomplete and said it was possible the size of the lift in home ownership could be revised down. But he said the directions of change and magnitudes were unlikely to change much.
An ownership rate of 72 per cent would be the highest since 1991, before 1999 when the Howard government cut the headline rate of capital gains tax making negative gearing more attractive. It currently stands at 66.7 per cent.
During the 2016 election campaign Prime Minister Turnbull said a Labor plan to wind back but not eliminate the negative gearing tax concession would "smash up home values", and "pull the rug out from under the property sector".
The claims were at odds with advice to the government at the time released on Monday under Freedom of Information laws that characterised the likely impact of Labor's proposals as "relatively modest".
Negative gearing allows investors in housing and other assets to deduct investment losses from their wage incomes for the purpose of calculating taxable income. The losses can be recouped later when the asset is sold for a profit, which is taxed at only half the rate of wage income.
Treasury found the arrangement predominantly helped high income families, with more than half of the benefit going to the top 20 per cent of earners.
Dr Uren said his modelling examined only what would happen after a transition process that might take several years.
Renters and owner-occupiers would be the biggest beneficiaries. Landlords, especially young, high earning landlords, would be the biggest losers.
Renters would benefit because although rents would climb by 2.4 per cent, the government would be in a position to compensate them and others with the extra $2 billion it would make in increased tax revenue.
"We are comparing two small changes," Dr Uren said. "One would be a small price change for renters and the other would be a small increase in transfers."
Young owner-occupiers would benefit from the lower house prices "as they can move up a housing ladder more easily".
Landlords who rely on borrowings would be "driven out of the market for investment properties".
Most are "young, but rich enough to afford the downpayment requirement for their investment". Other landlords would also scale back their holdings.
Thirty per cent of rental properties would be freed up and bought by Australians who would have otherwise rented. Almost every income group and every age group would increase its home ownership rate.
Acting Treasurer Kelly O'Dwyer disparaged the paper as "preliminary and incomplete", prepared by university academics.
She said Labor should not boast about a finding that house prices would go down and rents go up. It should "be of concern to every Australian, whether they're a prospective first home buyer who rents or they own their own home".
Labor Treasury spokesman Chris Bowen said it supported the direction of Labor's reforms and showed they would boost home ownership.