The problem with selling publicly owned assets is that after they are sold, they are gone forever.
The commitment to extend the Right to Buy to housing association tenants will distract from the central problem of a shortage of homes, not solve it.
Only in a country that fetishizes property ownership could political justification for the plan come on grounds of democratic fulfilment. An economic rationale is harder to find.
Nobody disputes that the idea may well be good news for individual tenants, but it is difficult to see where society as a whole benefits from such a denuding of social housing. Since the right was established in the 1980 Housing Act it has been taken advantage of by large numbers of Council tenants, who all received a windfall discount on the market value of their homes.
According to one estimate, about 36 per cent of those right-to-buy properties in London are now in the hands of private landlords.
They, in turn, often benefit from housing benefit payments. So quite what the advantage is for the taxpayer from footing the bill for the discounts offered, only to then end up subsidising private landlords, is unclear.
Under changes proposed by the Conservative Party in their manifesto and during the election campaign, housing association tenants will soon be permitted to apply to buy their home after three years in occupation for a discount of up to 35 per cent of its market value.
The discount rises depending on the number of years as a tenant, but will be capped in cash terms at £102,700.
The Government intends to pay for the policy by squeezing councils. Around 15,000 council houses in the top-third of values, some 0.4 per cent of the total stock, become vacant each year.
These would have to be be sold, raising £4.5 billion a year, according to the Conservatives. This money would be used to fund replacement properties, together with a new £1 billion fund to unlock brownfield land
It will also compensate housing associations for forcing them to sell their properties to tenants at below-market rates.
The proposals may be balanced and costed on a spreadsheet. But there are several problems on the ground, not least faith in the Treasury re-allocating funds from council house sales to new building schemes.
The idea that certain areas should only contain expensive owner-occupied or privately rented stock is also questionable in social terms.
There is also the issue of where the policy will leave housing associations. They may find it harder to secure funding for new building as lenders mark-down the value of their assets. The threat of losing their best housing stock just so that the more avaricious of their tenants can make a profit has them extremely concerned.
During the election campaign, Ruth Davison, director of policy at the National Housing Federation, asked: "Halfway through a programme of austerity why give £20 billion away to people who already live in secure homes?"
The Government needs to answer that question in both moral and economic terms for the policy to have credibility, particularly with 1.36 million households (about 3.4 million people) on the waiting list for social housing in England.
Nobody wants to discourage home ownership. But the real problem is on the supply side, and we should worry about a policy that pillages a system that actually works in its own market, one precisely arranged for those who cannot buy.
Concurrent policies to build 200,000 starter homes are to be applauded, but given the dismal record of housebuilding over the last decades, perhaps the applause should be put on hold until some front door keys have actually been handed over.
Otherwise, how odd to focus energy on encouraging those with a subsidised roof over their heads also to own it, at a stroke removing availability to others in need.