In 2016, Auckland upzoned approximately three-quarters of its residential land. Not a pilot program. Not a targeted corridor. Three-quarters of the city, reclassified to allow medium- and high-density housing where only low-density had been permitted before.
Between 2001 and 2018, Auckland’s adult population had grown 42 percent while its dwelling stock grew only 29 percent. The gap had been accumulating for nearly two decades. In the five years after the upzoning, housing construction surged to a record high of approximately 12 consented dwellings per thousand residents. By 2023, for the first time in a generation, housing supply in Auckland outstripped demand. Median rent as a share of median income fell from 22.7 percent in 2016 to 19.4 percent in 2023. Researchers using synthetic control methods — comparing actual Auckland to a constructed counterfactual — estimate the reforms held house prices 15 to 27 percent lower than they otherwise would have been.
The intervention worked. The data is not contested.
No major American city has done what Auckland did.
The consensus explanation for high housing costs in the United States is broadly correct: supply is restricted by zoning, and demand subsidies layered onto a supply-constrained market raise prices rather than solve them. This diagnosis has been mainstream in housing economics for at least two decades. The prescription — liberalize zoning, permit denser construction, reduce barriers to supply — follows directly from the diagnosis and is also broadly agreed upon by anyone who has run the numbers.
The gap between what the literature says and what gets enacted is not a knowledge problem.
The working hypothesis: Housing affordability policy in wealthy countries systematically selects for interventions that subsidize demand without touching supply constraints — not because those interventions are better designed, but because the constituency with the most concentrated political weight in housing policy is the one that benefits from supply restriction continuing.
Start with the mechanism that makes the selection visible.
Buying a home in the United States causes people to vote substantially more in local elections. This is not a correlation — a study published in the Journal of Politics, using deed-level data on more than 18 million individuals in Ohio and North Carolina, found a causal relationship using a difference-in-differences design. The homeowner turnout boost is nearly twice as large when zoning issues are on the ballot. The effect of homeownership on turnout increases with the price of the home purchase, which the authors interpret as evidence that asset investment is the operative mechanism.
The implication is structural. Homeowners vote at substantially higher rates than renters in general elections — a gap exceeding 20 percentage points — and the advantage is larger still in the off-cycle local elections where zoning decisions get made. Renters make up roughly one in three American households but a substantially smaller share of local election voters. The people most harmed by supply restriction are the least represented in the decisions that produce it.
The people most financially invested in supply restriction being maintained are the most represented. They show up in larger numbers, they show up specifically when zoning is on the ballot, and they show up more intensively when their home is more expensive. The political input function for local housing policy is not neutral. It is weighted toward one outcome by the structure of who participates.
Above the local level, the weighting is institutional rather than behavioral.
The National Association of Realtors spent $86.4 million on lobbying in 2024, more than any other organization in the United States. It has held the top spot among real estate industry spenders since 2006 and has spent approximately $850 million on lobbying since 1998. Its Realtors Political Action Committee contributes to candidates across both parties.
NAR’s stated mission is to represent real estate professionals. Its operational interests are more specific: transaction volume and asset price appreciation, because Realtors take a percentage of sale prices. Rising home prices do not harm NAR’s membership. They help it. Supply restriction that keeps prices elevated while transaction volume continues is the NAR member’s preferred market structure.
The policy positions follow from this interest. NAR has historically defended the mortgage interest deduction, which economists across the political spectrum have identified as a subsidy that disproportionately benefits wealthier homeowners and encourages the construction of larger homes rather than more homes. It has opposed real estate transfer taxes. It has supported down payment assistance programs, which increase the pool of buyers competing for a constrained supply. In 2024, it helped defeat a vacancy tax ballot measure in South Lake Tahoe, California, which would have applied financial pressure to owners holding units off the market.
None of these positions increase housing supply. Several of them reduce it or sustain the conditions that restrict it.
The policy toolkit that gets chosen in this environment has a consistent structure.
First-time homebuyer credits: The federal government offered up to $8,000 in tax credits for first-time buyers during the Great Recession, and Congress has repeatedly proposed credits as high as $15,000 since. The economic mechanism is well-understood — a demand subsidy in a supply-constrained market raises equilibrium prices. A 2022 Brookings analysis found that homebuyer assistance in supply-constrained markets raises prices for all buyers, transferring wealth from future purchasers to current homeowners who see their asset values increase. The policy is described as a homeownership affordability measure.
Down payment assistance: Same mechanism, same distributional outcome. The $25,000 in down payment assistance proposed during the 2024 presidential campaign drew immediate objections from housing economists: the American Enterprise Institute estimated the program would increase home prices by an average of 4.1 percent in affected markets. The program was proposed anyway.
Inclusionary zoning: The default affordability tool in high-cost American cities requires developers to include below-market units in new construction projects. At least 886 jurisdictions have adopted inclusionary zoning programs. The academic literature is not ambiguous about what these programs do: no study finds that inclusionary zoning increases housing supply or reduces prices broadly. The Mercatus Center has documented that inclusionary zoning functions as a tax on new construction, reducing overall construction rates, and this finding is consistent with the broader empirical record. The policy generates a small number of subsidized units, finances their construction by taxing the activity it claims to encourage, and is described as a housing affordability solution.
Each of these interventions shares a property: it does not threaten the asset values of existing homeowners. Each either directly increases those values, or creates the appearance of addressing affordability while leaving supply constraints intact.
The Auckland evidence creates a natural test. If the policy selection described above is driven by political economy rather than knowledge gaps or implementation difficulty, then the cities and countries that have achieved large-scale upzoning should share a feature: they overcame the political mechanism, not the technical one.
Auckland’s 2016 reform required the New Zealand national government to intervene in local land use decisions, removing the veto power of existing homeowners at the neighborhood level. Minneapolis’s 2040 Plan passed because reformers flipped enough city council seats to override entrenched opposition — and the Minnesota Court of Appeals lifted the injunction blocking it in May 2024 after years of litigation from neighborhood groups. A Middlebury College working paper found that five years after the plan’s reforms took effect, buyers and renters spent up to 34 percent less than they would have without the policy change.
Both cases required overriding the local political mechanism that normally produces policy selection in favor of supply restriction. Both produced measurable affordability improvements. Neither has been replicated at scale.
The technical problem is not what’s blocking replication.
What gets built instead is a permanent policy complex that gestures at affordability while maintaining the conditions that produce unaffordability. The mortgage interest deduction costs the federal government roughly $25 billion per year and disproportionately subsidizes the largest, most expensive homes. Low-Income Housing Tax Credits, the primary federal mechanism for subsidized housing production, are structured to generate returns for institutional investors and are administered through a competitive application process that produces a fraction of the units the shortage requires at many times the per-unit cost of simply building housing. First-time buyer credits arrive in the same legislative sessions where supply reform bills stall or get stripped of their operative provisions.
The pattern is not random. The interventions that pass are the ones that maintain or increase asset values for existing owners. The interventions that don’t pass are the ones that would increase supply, reduce prices, and transfer wealth from current owners to future ones.
This is the mechanism described in Part I of this series, operating one level down. There, the selection was against interventions that threatened private childcare markets and housing formation costs. Here, the selection is against interventions that would deflate residential asset values. The mechanism is identical. The policy domain is different. The outcome — the effective intervention not getting chosen — is the same.
A note on what this piece is not arguing. It is not arguing that homeowners consciously coordinate to block housing supply. It is not arguing that the National Association of Realtors is uniquely villainous. It is not arguing that first-time buyer credits or inclusionary zoning are designed in bad faith.
The mechanism doesn’t require any of that. It requires only that people vote their economic interests, that the people with the most concentrated economic interest in local housing decisions participate in those decisions at higher rates, and that the policy options that protect their interests get selected over the ones that don’t. The outcome is structural, not conspiratorial. Consciousness is not required. Self-interest, differential turnout, and institutional lobbying weight are sufficient.
The intervention that works is the one that threatens the asset. It keeps not getting built.
What would change my mind
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If a major American metropolitan area achieves a sustained reduction in rent-to-income ratio of 3 percentage points or more over five years using only demand-side interventions — buyer credits, down payment assistance, inclusionary zoning — without materially expanding supply, then the supply-side mechanism here is wrong and demand-side tools have an effect the literature hasn’t captured.
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If the academic literature establishes that the homeowner turnout premium on zoning decisions does not translate into measurable differences in zoning outcomes — that is, that high-turnout homeowner blocs are not actually producing different zoning decisions than would occur under representative participation — then the political mechanism described above is weaker than this piece claims.
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If a comprehensive supply reform bill passes Congress and achieves broad municipal adoption without requiring preemption of local zoning authority, then the veto point identified here — local political capture by existing homeowners — is not as structurally entrenched as the Auckland and Minneapolis cases suggest.
Related: The Policy That Keeps Getting Chosen — Part I of this series: how pronatalist policy systematically routes through tax architecture while avoiding the childcare and housing-cost interventions that would actually move fertility. What Zillow Can’t Show You — the data infrastructure that would allow buyers to see housing stress accurately is being eroded at the same moment the political economy is selecting against supply reform.
If you found this useful, the best thing you can do is forward it to one person who would push back on it. I’d rather be wrong in public than right in private.