For defenders of negative gearing, it's bad news. The pair explain that there's a good case for acting against the practice, dismissing alarmist claims it would disrupt the property market. Illustration: Kerrie Leishman For opponents of negative gearing, however, the news isn't as good as it seems. Since the resulting reduction in house prices isn't likely to be great, acting against the practice wouldn't do much to make home ownership more affordable. Investment in a rental property is negatively geared when so much of the cost of the property has been borrowed that the interest bill and other expenses exceed the earnings from rent. Why would anyone deliberately structure an investment to run at a loss? Partly because they can deduct that loss from their income from other sources, thus reducing their tax.

But that means they're still out of pocket for the remaining half or more of the loss. Why do that? Because they're hoping eventually to sell the place at a big capital gain, which should more than make up for the after-tax losses they've incurred. Mortgage applications were down in the June quarter suggesting the housing market is cooling. Credit:Erin Jonasson That's been more likely since 1999, when the Howard government introduced a 50 per cent discount on the rate of tax on capital gains. Daley and Wood disprove the dishonest claims that negative gearing is used by many people on modest incomes to get ahead. There may be a few of them, but the statistics show high income earners claim the lion's share of the benefits. The authors say there's no point of principle that supports our longstanding practice of allowing losses on property investments to be charged against wage income for tax purposes.

Very few other countries do this. It makes the housing market more volatile and reduces home ownership. It diverts capital from more productive investments while doing little to increase the supply of homes. They propose allowing losses on property investments to be deducted only against income from other investments, not against wages. This would save the budget $2 billion a year in the short term, falling to $1.6 billion a year as behaviour changes. But much of the attraction of negative gearing comes from its connection with the 50 per cent discount on the taxing of capital gains. They say there is a case for taxing capital gains more lightly than other income – mainly because much of the seeming gain comes just from the effect of inflation, which makes it illusory – but this doesn't justify a discount as great as 50 per cent. Allowing such a high discount (as well as allowing rental losses to be deducted against wage income) greatly reduces the government's tax collections, meaning it has to rely more heavily on other taxes. Those other taxes often do more to distort economic behaviour than taxing saving does.

In any case, empirical evidence shows people on high incomes save almost as much regardless of the tax rate. Measures intended to encourage saving mainly influence the vehicle through which wealthy people save – super or property or a bank account, for instance. As well, the high discount on capital gains tax creates opportunities for artificial transactions to reduce tax and encourages investors to focus too much on speculative investment – sit back and wait for capital gains to accrue – rather than investment that earns annual income by producing goods and services. Daley and Wood propose halving the capital gains discount to 25 per cent. This would save the budget about $3.7 billion a year. These policy proposals may sound the same as Labor's, but there are important differences. Labor promises that, for new investments undertaken from July 1 next year, deduction of losses against wage income will be permitted only for investments in newly built homes. Investments made before then will be unaffected, while losses on new investments in shares or existing properties may still be deducted against other investment income.

Labor promises to cut the capital gains discount to 25 per cent for all assets bought after July 1, 2017. All investments made before then will be unaffected. Daley and Wood criticise both proposals. Retaining existing negative gearing rules for prospective investments in newly built homes adds a new distortion that would, they believe, do little to increase the supply of homes. And they criticise Labor's plan to "grandfather" existing investments – for both negative gearing and the capital gains discount – leaving them unaffected by the change. A better way to minimise disruption to the market and to the expectations of existing investors would be to apply the changes to everyone, but phase them in equally over 10 years. If only making up our mind on the other election issues we'll face could be so easy.