Illustration: Andrew Dyson Credit:Andrew Dyson So if interest rates aren't the problem, the other factor is home prices. In a market economy like ours, the price of anything – whether ordinary goods or services, or an asset such as a house – rises when the demand for it exceeds its supply. For some years now, the supply of additional houses and units has failed to grow in line with "household formation" – young people getting married, people immigrating to Australia and couples splitting up. So inadequate growth in supply has been the real problem, caused by state and local governments placing too many legal obstacles and charges in the path of developers seeking to build new estates on the edge of the city and – perhaps more important – seeking to provide medium- and high-density "infill" closer in, where people increasingly prefer to live to avoid long commutes. The NSW Coalition government claims to have made progress in reducing these obstacles, and it's true that housing construction is growing faster in Sydney at present than it has been.

Illustration: Kerrie Leishman. But though the basic problem has been maintaining an adequate supply of appropriately located housing to meet the growing demand, the supply side of the problem isn't terribly visible to you and me. We're more conscious of the demand side, represented by the high and ever-rising cost of buying a place faced by our kids and other young people. What's more, we suffer from a kind of optical illusion. Your daughter and her partner are just sitting there saving, watching some invisible force push house prices further and further out of their reach. The trick is that while no single purchaser can move the market price, the combined demand of all purchasers can – and does, as we watch. Our natural, uneducated tendency to see the house price problem from the viewpoint of the individual buyer makes us susceptible to the pseudo solutions peddled by politicians seeking votes.

If only my daughter could get a bit of a leg-up in either putting together a sufficient deposit (say, by being allowed to dip into super) or in lowering the initial cost of the purchase (say, by staggering the cost of stamp duty), she could afford to take on the mortgage and she'd be right. See the weakness in that logic? If it helps your daughter and her partner, it also helps all the couples they're competing against to buy a place. Which means it gets your daughter nowhere. Actually, she's worse off. Since everyone can now more easily afford to pay the existing price, the prices of the homes they want to buy go even higher. As economists say, the benefit from the caring pollie's supposed helping hand is "capitalised" into the price of "ideal first homes". And that means the benefit of the measure ends up going not to first-home buyers but to first-home sellers. Economists have understood this perverse outcome since the year dot. Their rule is simple: when demand for housing is running ahead of supply, anything you do to make it easier for people to afford the high prices ends up only making prices higher, to the cost of buyers and the benefit of existing home owners. It's possible Hockey and Foley aren't sufficiently economically literate to have worked out that their proposals would be counterproductive. (Not to mention that Hockey's would leave young people's eventual retirement payouts significantly diminished because of their loss of compound interest, or that Foley's would leave fully financially committed couples with additional large lump-sum payments for five years.)

What's not credible is that these guys' economic advisers would have failed to warn them of the perverse consequences of their proposals. So they may just be fools, but my practice is to give their intelligence or competence the benefit of the doubt and assume they're knaves: they knew it was a con, but were confident most voters wouldn't see through it, so they proposed it anyway. And remember this: in any year, the number of voting home owners far exceeds the number of would-be home owners. So how could proposing a scheme that pretended to help first-home buyers while actually helping existing home owners cost you more votes than it gained? The pollies know that proposing phoney schemes to help young home buyers without actually lowering the value of the homes owned by the rest of us is exactly the kind of help we prefer them to offer. Ross Gittins is economics editor.