Rent caps save renters money if you ignore all flow-on effects
A single $15,590 figure is carrying the entire weight of Victoria's rent-cap debate — but what does the modelling actually measure?
The Victorian Greens have a number that does a lot of work: $15,590. That is how much the average Victorian renter would save by 2030, according to Parliamentary Budget Office modelling of a two-year rent freeze followed by permanent caps tied to wage growth. It is a concrete figure in an otherwise skeletal announcement, and it is doing the job any large, clean number is designed to do — end the conversation before it begins.
Melbourne's rental pressure is real; the question is whether this policy survives contact with it
Melbourne's rental market is genuinely under pressure. The June quarter figures the Greens cite are real: median weekly rents rose to $600, a 3.5 per cent jump that sits at the top of the national table. Renters are not imagining the squeeze. The policy is responding to something that exists.
The problem is not the diagnosis. It is the gap between the modelled number and the policy design required to actually produce it.
The PBO figure is a static projection. Feed it an assumption about what rents would otherwise do, impose a freeze, cap the trajectory to wage growth, and arithmetic delivers a savings figure. That is the model's job. What it cannot do is account for how landlords, developers, and prospective renters respond to those rules once they exist. And that response is not a theoretical objection — it is the mechanism through which rent control has historically undone itself.
The mechanism rewards exiting the market, not staying in it
The dynamics are not complicated. A landlord who cannot raise rents to market rates has three options: sell, convert the property to something unregulated (short-term letting, commercial use, owner-occupancy), or stop maintaining it. Each option removes supply or quality from the rental pool. Developers building new rental stock face the same calculation at the start — if future returns are capped at wage growth, the projects that pencil out at current construction costs stop pencilling out. The Australian Housing and Urban Research Institute notes that all variants of rent control, from hard freezes to soft stabilisation measures, carry supply-side risks in a low-vacancy market. Victoria's vacancy rate is already low. That is precisely the condition under which supply effects bite hardest.
The visible beneficiaries — current tenants — are politically present. The people who cannot find a rental because landlords exited the market, or who pay higher rents in the uncontrolled segment, are not.
The Greens' announcement does acknowledge the concern obliquely — there is a promise to build public housing, and the policy mentions tying rent increases to the property rather than the tenant to prevent eviction-and-reraise. Those are design features worth having. But they are bullet points, not a built policy, and none of them addresses the core incentive problem for private landlords. A ban on rent increases for the first two years of any new tenancy, stacked on top of a two-year freeze, is a rule that a landlord can solve simply by not offering the tenancy in the first place.
Controlled tenants benefit; everyone else absorbs the cost
The international evidence gives reason for caution. Economists who have studied rent control systems in New York, San Francisco, and across Europe find a consistent pattern: tenants in controlled units benefit, often substantially, while the broader rental stock contracts and rents for everyone else rise to compensate. The visible beneficiaries — current tenants — are politically present. The people who cannot find a rental because landlords exited the market, or who pay higher rents in the uncontrolled segment, are not. This is not an argument that controlled tenants should not be protected. It is an argument that the policy's total effect is not the same as its effect on the person already holding the tenancy.
None of this means rent stabilisation is impossible to design well. Some jurisdictions have managed supply risks through complementary investment incentives, inclusionary zoning, or direct public construction that makes the private sector's exit less consequential. The Greens gesture at public housing. But gesturing and designing are different things, and the announcement as it stands offers a savings figure and an enforcement ambition without the architecture that would let you assess whether the first survives the second.
The $15,590 figure is real in the same way a budget surplus projection is real before the spending decisions are made. The arithmetic works. Whether the conditions required to produce that arithmetic can be maintained in the real world, against the actual behaviour of landlords and developers in a city where supply is already constrained, is a question the announcement does not answer.
Renters in Melbourne are being asked to vote on a number. They deserve to be able to test it.
Frequently Asked Questions
How does the Victorian Greens' rent cap proposal actually work?
The proposal involves a two-year rent freeze followed by permanent caps tying future rent increases to wage growth. It also includes a rule preventing landlords from raising rents in the first two years of any new tenancy, designed to stop evictions followed by reraises.
Why do economists say rent control makes housing shortages worse?
When landlords cannot raise rents to market rates, they have incentives to sell, convert to short-term letting, or simply withhold properties from the rental market altogether. Developers face the same calculus upfront: if future returns are capped, projects that would otherwise proceed stop being financially viable, reducing new supply.
Does rent control actually save money for renters?
Tenants already in controlled properties typically do save money — the PBO's $15,590 figure reflects that direct effect. The problem is that the broader rental market tends to contract as landlords exit, pushing rents higher for everyone outside the controlled stock, particularly those trying to find a new rental.
What is the Parliamentary Budget Office and can it model market behaviour?
The PBO provides independent costings of policy proposals, but its modelling is based on stated assumptions rather than behavioural responses. A PBO savings figure shows what happens arithmetically if rents are held below their projected path — it cannot capture how landlords or developers would actually change their behaviour in response to the policy.
Has rent control worked anywhere overseas?
Some jurisdictions have managed supply-side risks by pairing rent controls with complementary measures — investment incentives, inclusionary zoning, or large-scale direct public construction. The consistent finding from cities like New York and San Francisco is that controls benefit sitting tenants while the uncontrolled rental segment absorbs higher rents and lower availability.