Land underuse and speculative vacancy persist in high-demand cities

At a glance — Even in cities where housing demand is most acute, a persistent stock of dwellings sits empty and valuable land is used well below its potential; the phenomenon is well documented across independent methods, though how much is speculative withholding rather than friction or zoning is contested. Evidence: Moderate (phenomenon well documented across independent methods; magnitude and causal attribution contested) · 9 supporting sources · 0 challenging Strongest support: Segú (2020) — French microdata show long-term vacancy large enough that a vacancy tax cut it about 13%, returning roughly 40,000 dwellings to use. No structural counter-evidence is currently wired; see Limits.

The Claim

Even in the cities where housing demand is most acute, a persistent stock of dwellings sits empty for years and valuable land is used well below its potential. The three strongest citations: Segú (2020, Journal of Public Economics) — French fiscal microdata show long-term vacancy substantial enough that a 1999 vacancy tax cut it measurably ("a 13% decrease in vacancy rates... specially concentrated in long-term vacancy"), with roughly 40,000 dwellings returned to use; Gyourko & Krimmel (2021, NBER/JUE) — in high-demand US metros, land is held below its market-implied intensity of use at gaps of "about $400,000" per quarter-acre in San Francisco and $150,000–200,000 in Los Angeles, New York and Seattle; and Prosper Australia (2024) — Melbourne water-meter data: "In 2023, 27,408 dwellings (1.5% of all homes) were left totally empty over the year," with 5.2% empty or barely used.

Honest limits: how much of this is speculative withholding rather than friction, second homes, or zoning-forced underuse is genuinely contested — the phenomenon is well documented; its size and cause are not settled.

The Mechanism

Holding valuable land or housing idle is often rational for the owner. An undeveloped or empty property is a real option on future appreciation: under price uncertainty, waiting can be worth more than renting or building now, and conventional property taxes barely penalize waiting (Cunningham 2006 confirms the option mechanism in Seattle parcel data). The speculative vacancy concept page develops the theory; land banking is the same calculus applied to development land, where — as Prosper's report argues — "developers strategically delay financially feasible developments" to maximise staged-release profits. The UK government's Letwin Review (2018) documented exactly this staged release on England's largest permissioned sites in high-demand areas — a median build-out period of 15.5 years, and just 3.2% of London mega-sites completed per year — though it attributed the slow pace to builders metering completions to the "market absorption rate" (selling no faster than the local market will buy without a price fall) rather than to speculation on future land prices. The Georgist relevance is direct: a land value tax converts the waiting option into an annual carrying cost (see LVT dampens land speculation).

The Evidence

Ordered by evidential weight:

1. Quasi-experimental tax evidence (Segú 2020). France's TLV produced a 0.8-percentage-point (13%) fall in vacancy in taxed cities, concentrated in long-term vacancy, with most freed dwellings becoming primary residences. This is the cleanest proof that a meaningful share of urban vacancy is neither frictional nor immovable: it responds to holding costs. A second, North American quasi-experiment points the same way: Vancouver's Empty Homes Tax — North America's first municipal vacancy tax (2017) — cut vacancy by "1.5 percentage points... a 21 percent decrease" in an independent difference-in-differences study, though the same study found no effect on rents (availability improved, affordability did not).
2. Vacant-lot price evidence (Gyourko & Krimmel 2021). The gap between what a lot sells for and what its land contributes at the intensive margin — the "zoning tax" — reaches six figures per quarter-acre precisely in the highest-demand coastal metros, showing systematic underuse of the most valuable urban land (attributed by the authors to regulation; see Counter-Evidence).
3. Consumption-based vacancy counts (Prosper Australia 2024, advocacy research with transparent method). Melbourne 2023: 27,408 dwellings (1.5%) used zero water all year; 97,861 (5.2%) empty or barely used — "equal to one in 20 homes across the city," and "more than two and a half years of new construction." The series has tracked the pattern since the early 2010s; Real Estate 4 Ransom popularized earlier editions.
4. Historical and aggregate corroboration. Hoyt's century of Chicago land values documents recurring speculative withholding; Hsieh & Moretti and Glaeser & Gyourko quantify the aggregate cost of high-demand cities operating below potential, whatever the mix of causes. A narrower historical illustration of the reverse mechanism — removing land-tax pressure removes the incentive to develop rather than hold — comes from Gaffney's New Life in Old Cities: in San Diego, a court order in 1926 reversed assessor Harris Moody's shift toward land-value taxation, after which, per Gaffney's secondary citation, "the city skyline froze for the next 75 years" — a single, second-hand anecdote rather than a study, but consistent with the real-option account above.

Counter-Evidence

• Institutional caution on the flipping channel. In the one place Canada's federal housing agency examined speculation directly, it found against it as the main driver: CMHC's September 2021 Housing Market Assessment reports that quick resales were "not the main source" of Montreal's price acceleration — a caution against over-attributing price dynamics to speculative flipping specifically, though it does not test the vacancy and land-banking mechanisms this page documents.
• Causal attribution: regulation, not speculation. The strongest mainstream reading of urban underuse is that legal density limits, not owner speculation, are the binding constraint — Gyourko & Krimmel attribute their entire land-price wedge to land-use regulation, and Glaeser & Gyourko (2018) diagnose high-demand-city housing costs as a zoning problem with non-fiscal remedies. On this view, taxing idle land without rezoning changes little, because building more is illegal regardless of holding costs. (The mechanisms are compatible — owners can land-bank within a zoning envelope — but the evidence does not apportion the blame.) The Letwin Review sharpens this caveat from a third angle: investigating slow build-out on large English sites, it explicitly rejected the crude "land banking for capital gain" thesis, locating the cause instead in the market absorption rate — builders release homes only as fast as the local market absorbs them at price. That is strategic supply restriction, but of a price-protecting rather than appreciation-betting kind; citing slow build-out as proof of speculative withholding overstates what the evidence shows.
• Measurement disputes. Consumption-proxy vacancy counts are contested: Prosper's own ABS electricity benchmark finds 1.4% zero-use against 1.9% in the water sample for the comparable year, and listing-based rental vacancy rates in the same cities run far lower because they measure a different thing. Zero utility use also captures renovation, probate, and sale transitions — not only speculation. The honest range, not the advocacy headline, should be quoted.
• Modest policy elasticities. The best-identified vacancy-tax effect (Segú) is real but modest — 0.8 percentage points — and a one-off stock release: Melbourne's entire vacant stock equals roughly 2.5 years of construction, so even full mobilization would not substitute for sustained new supply. Critics reasonably argue empty homes are a symptom and a margin, not the core of the housing shortage.

Strength of Evidence

Moderate. That long-term vacancy and land underuse exist at policy-relevant scale in high-demand cities is established across three independent methods (fiscal microdata, land transactions, utility consumption) on three continents, and the holding-cost mechanism has causal support. The claim is graded Moderate rather than Strong because magnitudes swing several-fold with measurement choices, and because the share attributable to speculative withholding — as opposed to regulation-forced underuse and ordinary friction — remains unresolved. Advocates can safely say "one in twenty Melbourne homes sat empty or barely used in 2023, and vacancy falls when you tax it"; they should not say "speculators are the cause of the housing crisis."

Further corroboration. Simpson (1933) counted roughly 335,000 vacant subdivided lots still unsold in 1920s Cook County — an eyewitness data point for speculative land withholding at scale, though he folded it into the wider Depression.

See Also

• Speculative Vacancy · Land Speculation · Land Monopoly
• LVT dampens land speculation — the prescription-side companion page
• Cunningham (2006), Seattle real options — the waiting mechanism
• Letwin Review (2018) — UK government evidence on slow build-out of permissioned land
• Prosper Australia · Narrative: The Housing Crisis Is a Land Crisis
• High land rents suppress productivity
• Gaffney (2006): New Life in Old Cities — the San Diego "frozen skyline" historical illustration

Sources

1. Mariona Segú (2020), "The impact of taxing vacancy on housing markets: Evidence from France," Journal of Public Economics 185, 104079. DOI · wiki summary — used for the quasi-experimental evidence that long-term vacancy is real and tax-responsive (B-claims).
2. Joseph Gyourko & Jacob Krimmel (2021), "The impact of local residential land use restrictions on land values...," NBER WP 28993 / JUE 126, 103374. NBER · wiki summary — used for the underuse magnitudes and the regulation counter-frame (B-claims).
3. Prosper Australia (2024), Speculative Vacancies 11: Empty Homes in Melbourne 2019–2023. PDF · wiki summary — used for the Melbourne vacancy counts and land-banking argument (B-claims from advocacy research; method transparent, benchmarked against ABS data).
4. Christopher R. Cunningham (2006), "House Price Uncertainty, Timing of Development, and Vacant Land Prices," JUE 59(1). DOI · wiki summary — used for the option-value mechanism (B-claim).
5. Edward Glaeser & Joseph Gyourko (2018), "The Economic Implications of Housing Supply," JEP 32(1). wiki summary — used for the zoning counter-frame (B-claims).
6. Oliver Letwin (2018), Independent Review of Build Out: Final Report, Cm 9720, MHCLG / HM Treasury. GOV.UK · wiki summary — used for the slow build-out of permissioned land in high-demand areas (15.5-year median; 3.2%/yr London mega-sites) and the absorption-rate refinement of the land-banking mechanism (B-claims; government review).
7. Mason Gaffney (2006), "New Life in Old Cities," masongaffney.org. wiki summary · PDF — used for the San Diego "frozen skyline" historical anecdote (D-claim: Gaffney's own citation of an unpublished secondary source, not independently verified in this pass; corroborating only).