This is not a minor offence. It is the latest instalment in a decades-long project to pollute British housing discourse with bad economics dressed up as moral conviction, and the BBC, to its considerable shame, has just published it.
Alice Roberts of CPRE London, the capital’s arm of the countryside-protection lobby that has spent the better part of a century treating the green belt as Holy Writ and the under-35s as an inconvenience to be managed, is “VERY happy” (her capitals, not mine) to see the BBC run the headline “Affordability, not shortage, causes London housing crisis.” She treats it as vindication of the Letter to London, that 2024 missive in which a coalition of campaigners, academics, and the professionally aggrieved implored journalists to stop writing about supply as though it mattered. The triumphalism is not premature. It is simply telling. It tells you precisely what kind of NIMBY belief system you are dealing with: one in which forty years of empirical urban economics is a “claim” to be “scrutinised,” and a single misread OBR forecast is vindication of their misunderstanding.
Let us be clear about what this is. It is not heterodox economics. It is not a brave challenge to a complacent consensus. It is a belief system. One in which housing markets can be reasoned about by analogy to one’s own front door; in which the visible villain (the developer’s profit margin, the foreign-sounding name on a Land Registry entry, the new block of flats interrupting the skyline) is always the cause; and in which the invisible victim (the thirty-two-year-old in his childhood bedroom; the family in a one-bed; the couple who never formed) is conveniently nothing at all.
It is the same instinct that produced rent control in 1915, the Town and Country Planning Act 1947, and the calamitous 2018 Viability SPG which shut down the land market in a global city. It’s the conviction that one’s gut is a more reliable guide to housing markets than the regression discontinuities, and that anyone who points to the data is a shill. It is moral certainty masquerading as analysis, and it has captured a significant fraction of the British commentariat. Across both divides.
The dismantling of the supply-sceptic case this week came courtesy of Valentin Boboc (@doktor_val), whose thread performs the unglamorous but essential work of reading the ONS definitions the Letter to London tendency declines to read themselves. The supply-sceptic case rests on a single talking point: there are roughly 1.1 dwellings per household in the UK; ergo no shortage; ergo the problem must be “affordability” or, in Boboc’s phrase, “some other type of conspiracy.” The ratio is offered as though it settled the question. It does not even pose it.
Boboc’s argument is compressed and lethal. The ratio divides two arbitrary numbers. A “dwelling,” per the ONS, is a self-contained unit with its own kitchen, bathroom, and lockable door. A “household” is one or more people sharing cooking facilities at a single address. By construction, the household count is “endogenous” to the housing stock, it counts the living arrangements that have already occurred under prevailing prices, not the arrangements people would choose if they could afford otherwise.
A thirty-two-year-old living in his childhood bedroom does not register as a suppressed household. He registers as part of his parents’ household. Count: one. Ratio: preserved. The crisis is rendered invisible by the very statistic deployed to deny it. This is not a methodological quibble. It is the difference between counting people at a bus stop and concluding the buses run on time.
The ONS’s own Family and Households dataset (2023) records 4.9 million adults aged 15-34 living with parents, up from 2.7 million in the late 1990s, which was an 80 per cent increase against population growth of 11 per cent. The Resolution Foundation’s *Housing Outlook* (Q4 2023) found headship rates among under-35s have fallen by roughly a quarter since 2003. The 2021 Census recorded London’s overcrowding rate at 11.1 per cent, the highest in England (ONS, 2022). These are not the features of a market clearing comfortably at 1.1 dwellings per household. They are the fingerprints of demand suppressed by price, precisely the demand the ratio cannot, by construction, see.
Bramley’s needs-based estimates for Crisis and the NHF (2018) put true need at 340,000 homes per annum. Centre for Cities (The Housebuilding Crisis, 2023) puts the cumulative shortfall against European norms at 4.3 million dwellings since 1947. Against either benchmark, the OBR’s modelled <1 per cent price effect of 1.5 million homes (October 2024, EFO) is not evidence that supply does not matter; it is evidence that the dose was sub-marginal. Vacancy rates are at historic lows (MHCLG, 2024). Markets that clear comfortably do not exhibit historic-low vacancy and 80 per cent growth in adult children at home. They exhibit equilibrium. This exhibits sky high rents, unaffordable prices, and councils going bankrupt over temporary accommodation bills.
Now consider what London is actually delivering. The Government’s Standard Method requires the capital to deliver 88,000 homes a year. In 2025, reported private starts came in at 5,891. Only a 94 per cent shortfall against target, described by industry figures as a systemic failure rather than a cyclical slowdown (Homebuilding & Renovating) . Molior’s research found that twenty-three of London’s thirty-three boroughs recorded zero new housing starts in the first quarter of 2025 alone, with the capital on track for just 5,000 starts across the whole year, which is 5.7 per cent of the 88,000 required (Bidwells) . Completions in 2024-25 were 28,576, well below target, and Molior project just 9,100 completions in 2027 and again in 2028. Barely a fraction of the 440,000 London is meant to deliver this Parliament (Bidwells) . Planning permissions have collapsed to their lowest level since records began in 2006, with just 966 projects approved in the year to June 2025, and London’s share of national housing delivery has shrunk from 20 per cent a decade ago to 15 per cent today (Hbf) . Against the 88,000 target, output would need to more than double, or increase by 175 per cent, to comply (Hbf) . This is not a market suffering from oversupply mistaken for affordability stress. This is a market that has completely stopped functioning.
And the international evidence, conspicuously absent from the Letter to London, is not ambiguous. Greenaway-McGrevy and Phillips (Economic Policy, 2023) found Auckland’s 2016 upzoning reduced rents by 21-33 per cent against counterfactual within five years. Asquith, Mast and Reed (Review of Economics and Statistics, 2021) found new market-rate housing in low-income American neighbourhoods reduced nearby rents by 5-7 per cent within three years. Pennington (Stanford, 2021) found new construction reduced displacement risk for incumbent low-income tenants. Tokyo has produced flat real rents for two decades under national-level zoning (MLIT, FT 2023). Minneapolis recorded rent growth of one per cent against fourteen across the rest of Minnesota after abolishing exclusionary zoning (Pew, 2024). Each is a measured outcome, in a comparable jurisdiction, achieved within a parliamentary term. None was achieved by writing a Letter.
London, meanwhile, completed 35,000 homes in 2023-24 against a London Plan target of 52,300 (GLA Housing Delivery Monitor, 2024), approves new dwellings per capita at roughly half the rate of Paris (Centre for Cities, 2023), and rings itself with a green belt three times its built footprint, much of it neither green nor accessible, which CPRE will defend to the last intensive horse paddock. The capital then convenes a coalition to argue that the binding constraint is not the thing it has spent forty years failing to do.
This is where the indulgence has to stop. The *Letter to London* tendency is not contributing to debate. It is degrading it. It takes a settled empirical question, does building more homes lower their price? And re-litigates it weekly with the same tools the anti-vaccine movement uses on epidemiology: motivated reasoning, statistical innumeracy, definitional sleight, and the bottomless reservoir of moral certainty that comes from believing your interests and the public interest are identical.
And then when the BBC publishes this material under a news headline rather than an opinion banner, it does not stage a debate. It launders a belief system. It tells the renter in the HMO, the couple priced out of family formation, and the thirty-two-year-old in the childhood bedroom that their predicament is not a shortage but a vibe caused by a profit driven evil; that the laws of supply and demand pause politely at the M25; that the people defending the asset values of incumbent owners are in fact the brave dissidents speaking truth to a developer-industrial complex. These narratives barely count as journalism. Why? Because every time it is the people who got the ladder, explaining to the people without one, that ladders don’t exist.
So here is the offer, with no gloves on. To CPRE London, to the *Letter to London* signatories, to the BBC sub-editor who waved this through, and to every commentator who has been browbeaten into treating “build more homes” as a contested hypothesis rather than the settled finding of forty years of urban economics: name the city. One city. Anywhere on earth, in any decade, that solved housing costs without building housing.
Produce the case study. Submit it to peer review. Until you can, the position is not heterodox, not contrarian, not a brave challenge to neoliberal orthodoxy. It is a generation of homeowners, sitting on appreciated assets behind a green belt they did not plant, telling a generation of renters that economics is a conspiracy theory, and finding, to their evident delight, a public broadcaster willing to print it.
The capitals are doing a lot of work. The evidence is doing none. And the children, as Boboc gently reminds us, would quite like to move out.
