In 1960, the median price of a new home in the United States was $11,900, roughly two times the median annual household income of $5,600. A young factory worker, a schoolteacher, a nurse — someone who had gone to work after high school and saved modestly for a few years — could plausibly buy a house in most American cities. The American Dream's material core, the owned home in a decent neighborhood with good schools, was within reach of the American median. That calculus has changed so dramatically that younger Americans discussing it with their parents often sound like they are describing different countries, which in economic terms they largely are. By 2022, the median US home price had risen to roughly $430,000 against a median household income of about $70,000 — a ratio of over six to one. In San Francisco, the ratio exceeds fifteen to one. In the year 2024, a household earning San Francisco's median income qualifies for a mortgage on a home at roughly the fifteenth percentile of that city's market.
This is not an accident, and it is not a mystery. The research on housing unaffordability is unusually consistent for social science: housing is expensive where supply is legally constrained relative to demand. The cities where housing costs have risen most severely are, without exception, cities where the political and regulatory barriers to building new housing are most intense. The cities where housing has remained relatively affordable — Houston, Tokyo, most of the American South and Midwest — are places where building is relatively easy. The divergence is not a market failure in the conventional sense; it is a market outcome from a system of regulations deliberately designed to produce it, maintained by a political economy that benefits those who already own property at the expense of those who do not.
The question is not really "what causes the housing crisis?" The mechanics are well understood. The harder question — the one that explains why the crisis persists despite its being understood — is why the political system has been so resistant to solutions that economists across the ideological spectrum broadly agree on.
"If you think you can separate the geography of opportunity from the affordability of housing, you're wrong. The places where housing costs the most are the places where economic opportunity is concentrated. The housing crisis is an opportunity crisis." — Alain Bertaud, Order Without Design (2018)
Key Definitions
Exclusionary zoning: Land use regulations — including single-family zoning, minimum lot sizes, parking minimums, and height limits — that restrict density and effectively prohibit the construction of affordable housing types in desirable neighborhoods.
Housing supply elasticity: The responsiveness of new construction to rising prices. High-elasticity markets (Houston, Tokyo) produce more housing when prices rise; low-elasticity markets (San Francisco, New York) do not, because regulatory barriers prevent supply response.
NIMBYism: "Not In My Back Yard" — the tendency of existing residents to oppose new development near their homes, typically citing concerns about density, traffic, school capacity, neighborhood character, or home values.
YIMBY movement: "Yes In My Back Yard" — a political movement advocating for zoning reform and increased housing construction, typically framing housing supply as a matter of both economic efficiency and social equity.
Rent control: Price ceilings on rents, which limit how much landlords can charge existing tenants. Distinct from rent stabilization, which limits the rate of rent increases.
Land value tax: A tax on the location value of land, excluding the value of buildings or improvements. Proposed by Henry George (1879) as a way to capture publicly-created land value and incentivize efficient land use.
Homevoter hypothesis: William Fischel's argument that homeowners treat their home as their primary financial asset and vote in local elections to restrict new development that might reduce their home's value or change neighborhood character.
The Basic Economics: Supply Meets a Wall
Housing economics begins with a straightforward supply and demand framework that is not in dispute. When more people want to live in a city than there are homes for them, prices rise. The appropriate market response is for developers to build more homes, attracting new supply until prices stabilize at a level that covers construction costs plus a normal profit. This is how commodity markets generally work, and it is why the price of shirts and cars has not risen fifteen-fold in real terms since 1960.
What makes housing different is that supply is regulated in ways that no other commodity is regulated. Developers who want to build more shirts can do so by renting factory space and hiring workers. Developers who want to build more homes in San Francisco must first obtain a zoning variance, a conditional use permit, an environmental impact review under the California Environmental Quality Act (CEQA), and survive a public hearing process in which any neighbor who objects can trigger years of legal challenges. The result is that when demand rises in San Francisco, new supply does not follow — it is legally blocked — and prices rise instead.
Edward Glaeser and Joseph Gyourko demonstrated this mechanism with rigor in a series of papers beginning in 2003. In "The Impact of Zoning on Housing Affordability" (2003), they showed that in high-cost cities, housing prices are far above the cost of construction — sometimes three or four times above — and that this gap is not explained by land costs or construction costs alone. It is explained by what they called the "zoning tax": the premium that buyers pay because regulations prevent the supply from responding to demand. In Houston, construction costs plus land account for most of the home price. In San Francisco, they account for perhaps a third of it. The rest is the zoning tax.
Exclusionary Zoning: The Mechanism
Single-family zoning is the primary supply-restricting mechanism in most American cities. By designating the majority of residential land as available only for detached single-family homes — prohibiting duplexes, triplexes, apartment buildings, and any other multi-family form — single-family zoning artificially caps the number of homes that can be built on most residential land.
Consider a 5,000-square-foot lot in a neighborhood within walking distance of jobs and transit. Single-family zoning allows one home on that lot. Under a moderate density zoning regime, that same lot could accommodate a three-story building with six apartments. Under Tokyo's zoning rules, it might accommodate more. The supply of homes in the neighborhood is thus the neighborhood's land area divided by the minimum lot size — a regulatory ceiling, not an economic outcome.
The additional restrictions compound the effect. Parking minimums — requirements that each new residential unit include one or two off-street parking spaces — add $30,000 to $50,000 per space in construction costs in dense urban areas, where structured parking requires expensive excavation or concrete. They also consume land that could otherwise be used for housing. Many new apartment projects in American cities would be economically viable if they did not have to provide parking; the parking requirement tips the financial calculus into loss. Height limits cap density in areas that could efficiently absorb more people. Setback requirements push buildings away from property lines, reducing buildable area. Minimum unit size requirements prevent the construction of smaller, cheaper units that many single people and young adults would prefer.
The California Case: Dysfunction at Scale
California is the sharpest illustration of the housing crisis at work. The state has the largest economy in the United States, a concentration of high-wage jobs in technology, finance, and professional services, and among the highest housing costs in the world. The Los Angeles metro area adds roughly 100,000 jobs per year and builds roughly 25,000 housing units. San Francisco adds roughly 30,000 jobs per year and builds roughly 3,000 housing units. The mathematics of this mismatch produce predictable outcomes: displacement of lower-income residents, homelessness, hours-long commutes from affordable exurbs, and the migration of workers who cannot afford California to other states.
The political architecture of this dysfunction is distinctive. Proposition 13, passed by California voters in 1978, capped property tax increases at 2% per year regardless of actual home value appreciation. A homeowner who bought in San Francisco in 1978 for $80,000 pays property tax on an assessed value that may be $100,000 today, while their neighbor who bought the same type of house in 2020 for $2 million pays taxes on the full current value. The resulting underassessment of long-held properties creates perverse incentives: long-term homeowners have enormous untaxed paper gains that new development might threaten, while local governments depend on new construction to generate new property tax revenue, yet face political resistance to that construction from Prop 13 beneficiaries who have no fiscal stake in accommodating growth.
California's zoning is administered by 478 independent municipalities, each with its own land use code. Wealthy suburbs in the Bay Area — Atherton, Hillsborough, Palo Alto — are economically integrated into a regional labor market but are not required to house any particular share of the workers who work in that market. They zone for low density, receive the benefits of regional economic growth, and externalize the housing costs onto other municipalities or onto lower-income households who commute from affordable exurbs.
The Racial Origins of Exclusionary Zoning
Richard Rothstein's "The Color of Law" (2017) documented something that many American urbanists had suspected but had not been fully established in mainstream discourse: exclusionary zoning in the United States has explicitly racial origins. The Supreme Court's decision in Buchanan v. Warley (1917) struck down explicit racial zoning — ordinances that designated neighborhoods as white or Black by law. The response by white property owners and local governments was to find race-neutral mechanisms to achieve the same segregation: racially restrictive covenants in deed language, redlining by the Federal Housing Administration (which refused to insure mortgages in racially integrated neighborhoods), and single-family zoning, which, in the context of deliberate public policy steering Black families into urban apartments and white families into suburban homes, functioned as a proxy for racial exclusion.
Rothstein's argument is not merely historical. The residential segregation created by these policies persists today in the spatial distribution of schools, wealth, and neighborhood quality. Exclusionary zoning continues to prevent the integration of wealthy, white-dominated suburbs in major metropolitan areas. The YIMBY framing of housing reform as racial justice rests on this history: loosening single-family zoning is, in part, undoing a racial geography that was deliberately constructed.
NIMBYism as Political Economy
William Fischel's "The Homevoter Hypothesis" (2001) offers the political economic explanation for why exclusionary zoning persists despite its costs. Homeownership concentrates a household's wealth in a single, illiquid, geographically fixed asset — the home. Unlike a stock portfolio, a house cannot be diversified. Its value is acutely sensitive to neighborhood conditions: nearby development, school quality, crime rates, traffic. Homeowners therefore have unusually strong incentives to monitor and influence local governance, because local decisions directly affect their primary asset.
Renters, by contrast, are mobile — they can move when conditions deteriorate — and do not hold an asset whose value depends on neighborhood stability. They have weaker incentives to vote in local elections and weaker organizational capacity in local politics. The political result is a systematic overrepresentation of homeowner preferences in local land use decisions, and homeowner preferences systematically favor restricting new supply.
The community opposition to new housing — variously citing traffic, parking, school capacity, neighborhood character, and design aesthetics — is largely epiphenomenal to the underlying financial interest. Studies of NIMBY opposition consistently find that the strength of opposition is correlated with proximity to the proposed development and with homeownership rates, rather than with the specific characteristics of proposed projects. Opposition to a luxury tower and opposition to affordable housing units are both equally intense in most high-cost neighborhoods, suggesting that the specific nature of the proposed development matters less than its existence.
Rent Control: Protection vs Supply
The debate over rent control is one of the most persistently contentious in housing policy, but the empirical research has become unusually clear. Diamond, McQuade, and Qian's 2019 study in the American Economic Review used San Francisco's 1994 ballot initiative — which extended rent control to smaller apartment buildings — as a natural experiment. Because the initiative applied to buildings constructed before a specific date, the authors could compare outcomes for tenants in similar buildings on either side of the eligibility cutoff.
The benefits for protected tenants were real and substantial. Tenants in rent-controlled units paid roughly 15% less than market rates and were 19% more likely to remain in their homes over the following two decades. In a city where displacement is a major quality-of-life issue and where long-term residents are being pushed out by rising costs, these protections represent genuine value.
But landlords responded to rent control by removing units from the rental market — converting apartments to condominiums, demolishing and redeveloping, or selling to owner-occupants. The net effect was a 15% reduction in the supply of rental housing in San Francisco, and a consequent increase in rents in the uncontrolled market. The study estimated that rent control, in this case, reduced the welfare of renter households in aggregate, even as it provided significant benefits to the subset with protected units.
This does not resolve the normative question: whether protecting existing tenants from displacement — even at some cost to aggregate housing affordability — is a legitimate policy goal. It is. But the evidence suggests that rent control is better understood as a tenant protection measure than as a housing affordability solution, and that policymakers who want to address affordability broadly need to address supply.
What Actually Works
The international comparison is instructive. Tokyo's housing costs are remarkably moderate for a metropolitan area of 37 million people, despite sustained in-migration and high incomes. The primary explanation is Japan's national zoning framework, which limits local governments' ability to impose restrictive zoning and has maintained a relatively permissive development environment. Tokyo added roughly 170,000 new housing units in 2022, compared to roughly 23,000 in Los Angeles, a city with roughly one-third of Tokyo's population. Tokyo's greater permissiveness has meant that new supply consistently absorbs demand, preventing the price spirals that characterize restricted markets.
Vienna's model is different: roughly 60% of Vienna's residents live in some form of publicly subsidized housing, including the city's famous "social housing" (Gemeindebau) apartments. Vienna has sustained political commitment to public housing investment since the 1920s, when the Red Vienna municipal government built enormous housing complexes as a deliberate social policy. The result is a housing market in which the publicly subsidized sector moderates private market rents by providing a genuine alternative — not marginal public housing for the very poor, but quality social housing for a broad cross-section of income levels.
Singapore's Housing Development Board has built and owns housing for approximately 80% of Singapore's population. Virtually every Singaporean family lives in a public apartment at some point in their lives, at subsidized prices, with the option to purchase and resell in a secondary market. Singapore's housing policy is an extreme case that depends on its particular political economy — a small, wealthy city-state with a one-party government — but it demonstrates that the housing market can be organized very differently from the US model.
Henry George's land value tax, proposed in "Progress and Poverty" (1879) and advocated by contemporary economists including Joseph Stiglitz, Paul Romer, and Alvin Rabushka, addresses the speculative element in housing costs by taxing location value rather than building value. Because land value is created by public investment — infrastructure, schools, parks — and by the existence of a surrounding community rather than by the landowner's own effort, taxing it does not discourage productive activity. Taxing building value, by contrast, penalizes construction and improvement. A land value tax creates strong incentives for property owners to develop land efficiently rather than hold underdeveloped land for speculative appreciation. Several jurisdictions — Pennsylvania, parts of Australia and Estonia — use split-rate property taxes that shift some of the tax burden from buildings to land, with positive supply effects.
The Cost of Not Building
Chang-Tai Hsieh and Enrico Moretti's 2019 paper in the American Economic Review estimated the aggregate cost of housing supply restrictions in terms of foregone economic output. By modeling the increase in total factor productivity that would result from workers being able to locate in the cities where their skills are most productively deployed — if, that is, they were not priced out of those cities — Hsieh and Moretti estimated that US GDP would be approximately 9% higher, representing roughly $2 trillion annually, if New York, San Francisco, and San Jose had maintained median housing supply elasticity since 1964.
This figure captures only the productivity loss from workers not being in the right city. It does not capture the welfare loss from long commutes, the displacement of communities, the homelessness that is the acute end of housing unaffordability, or the foregone earnings of workers who remain in lower-productivity locations because they cannot afford to move to higher-productivity ones.
The housing crisis is not a law of nature. It is a policy choice — the accumulated outcome of thousands of local zoning decisions, fiscal incentives for homeownership over rental, and political economies that prioritize existing homeowners over future residents. Every country and city that has maintained housing affordability has done so through deliberate policy: permissive zoning, public investment in social housing, land value taxation, or some combination. The American housing crisis is distinctive in its severity precisely because American housing policy — fragmented, captured by homeowner interests, historically shaped by racial exclusion — has been unusually hostile to supply.
For related analysis of how urban planning shapes economic and social outcomes, see How Urban Planning Works. For the broader economic forces driving inequality that housing costs exacerbate, see Why Inequality Grows. For the foundational economic framework, see What Is Supply and Demand.
References
- Glaeser, Edward L. and Joseph Gyourko. "The Impact of Zoning on Housing Affordability." Economic Policy Review 9(2): 21-39, 2003. https://doi.org/10.3386/w8835
- Diamond, Rebecca, Tim McQuade, and Franklin Qian. "The Effects of Rent Control Expansion on Tenants, Landlords, and Inequality: Evidence from San Francisco." American Economic Review 109(9): 3365-3394, 2019. https://doi.org/10.1257/aer.20181289
- Hsieh, Chang-Tai and Enrico Moretti. "Housing Constraints and Spatial Misallocation." American Economic Journal: Macroeconomics 11(2): 1-39, 2019. https://doi.org/10.1257/mac.20170388
- Fischel, William A. The Homevoter Hypothesis: How Home Values Influence Local Government Taxation, School Finance, and Land-Use Policies. Harvard University Press, 2001.
- Rothstein, Richard. The Color of Law: A Forgotten History of How Our Government Segregated America. Liveright, 2017.
- Bertaud, Alain. Order Without Design: How Markets Shape Cities. MIT Press, 2018.
- George, Henry. Progress and Poverty. D. Appleton and Company, 1879.
- Gyourko, Joseph and Jonathan Hartley. "Regulation and Housing Supply." NBER Working Paper No. 20536, 2014. https://doi.org/10.3386/w20536
- Buchanan v. Warley, 245 U.S. 60 (1917). https://supreme.justia.com/cases/federal/us/245/60/
Frequently Asked Questions
Why is housing so expensive in major cities?
Housing is expensive in major cities primarily because supply has not kept pace with demand. The basic economic logic is straightforward: when the number of people who want to live somewhere grows faster than the number of homes available, prices rise. What makes housing distinctive — and what makes the crisis so persistent — is that housing supply in most desirable cities is legally constrained in ways that prevent the normal market response of building more when prices rise. In 1960, the median US home cost roughly two times median annual household income. By 2022, that ratio had risen to over six times. The divergence accelerated after roughly 1970, which corresponds closely to the period when exclusionary zoning became pervasive across American metropolitan areas and when the political power of existing homeowners became sufficient to block new development in most high-demand locations. The cities with the most severe housing shortages — San Francisco, New York, London, Sydney, Amsterdam — are places where economic opportunity is concentrated but where regulatory and political constraints on building are also intense. Cities like Houston and Tokyo, which have maintained relatively permissive building regulations, have seen much more moderate price increases despite strong demand. The research on this is robust: economists Edward Glaeser of Harvard and Joseph Gyourko of Penn's Wharton School demonstrated in a series of influential papers beginning in the early 2000s that housing prices in expensive cities are determined primarily by the elasticity of supply — how readily new housing can be built — rather than by demand per se. High-demand cities with elastic supply (Houston) have moderate prices; high-demand cities with inelastic supply (San Francisco) have extreme prices.
How does zoning create housing scarcity?
Zoning creates housing scarcity by legally restricting the density, type, and location of residential construction, preventing the building of enough homes to accommodate demand even when economic incentives to build are strong. Single-family zoning — which prohibits the construction of apartments, duplexes, or any multi-family housing on most residential land in most American cities — is the primary mechanism. In cities like Los Angeles, San Jose, and Minneapolis (before its 2040 plan), over 70% of residential land was historically zoned exclusively for single-family detached homes. On this land, it is illegal to build a duplex, a townhouse, or a small apartment building regardless of what buyers or renters would pay. Additional restrictions compound the effect: minimum lot sizes require each home to occupy a minimum amount of land, preventing efficient use of space; setback requirements mandate distances between buildings and property lines; parking minimums force developers to build parking spaces that consume land and add cost even when residents do not own cars; height limits cap building density even in areas with strong demand. These rules reduce housing supply in two ways: directly, by prohibiting the construction of more homes than the rules allow; and indirectly, by making development more expensive and time-consuming, reducing the economic viability of projects that would otherwise be built. The political economy of zoning is the key to understanding its persistence: existing homeowners benefit from housing scarcity because it raises the value of their homes, and they vote in local elections at much higher rates than renters or would-be residents who have not yet arrived. William Fischel's 'homevoter hypothesis' formalizes this: homeowners treat their home as their primary financial asset and vote to restrict new development that might compete with or change the character of their neighborhoods.
What does the research say about rent control?
The research on rent control shows a consistent pattern: it provides significant benefits to the tenants who hold controlled units, at the cost of reducing the overall supply of rental housing and increasing rents for everyone else. The most rigorous recent study is Diamond, McQuade, and Qian (2019), published in the American Economic Review, which used San Francisco's 1994 rent control expansion as a natural experiment. The researchers found that tenants in rent-controlled apartments paid roughly 15% less in rent than market rates and were 19% more likely to remain in their homes — a genuine and substantial benefit for the people protected. But landlords responded by converting rental units to condominiums, selling to owner-occupants, or redeveloping buildings — all of which remove units from the rental market. The net effect was a 15% reduction in the supply of rental housing in San Francisco. Because the total supply of rentals shrank while demand continued to grow, rents in the uncontrolled market rose by 7%, with cumulative effects that likely contributed significantly to San Francisco's housing cost crisis. The Diamond et al. results are consistent with decades of theoretical economic analysis and with earlier empirical work. Economists across the political spectrum — from Milton Friedman to Paul Krugman — have argued that price ceilings below market rates reduce supply over time. This does not mean rent control has no role: it provides genuine protection for existing tenants against displacement, which is a real harm with real costs to individuals and communities. The evidence suggests that rent control is a tool for protecting existing tenants rather than solving housing affordability, and that it tends to worsen affordability at the margin for the broader population seeking housing.
What is the YIMBY movement?
YIMBY stands for 'Yes In My Back Yard' — a political movement and loose coalition that advocates for increased housing construction, denser development, and the reform of zoning laws that restrict supply. It emerged in the early 2010s primarily in San Francisco and other high-cost California cities as a response to the housing crisis and to the entrenched NIMBY ('Not In My Back Yard') politics of existing homeowners. The YIMBY movement is unusual in that it draws support from across conventional political lines. On the left, YIMBY advocates argue that restrictive zoning is a form of inequality — a mechanism by which wealthy homeowners in desirable neighborhoods block the construction of housing that would benefit lower-income renters and workers. Richard Rothstein's 'The Color of Law' (2017) documented the explicitly racial origins of exclusionary zoning in the United States, arguing that single-family zoning was deployed after Buchanan v. Warley (1917) to achieve racial segregation that explicit racial zoning could no longer legally mandate. This framing has made housing supply reform a racial justice argument as well as an economic one. On the right and center, YIMBY advocates argue for market-rate development and the removal of regulatory barriers, framing housing reform as deregulation. The movement has achieved legislative successes, particularly in California: Senate Bills 9 and 10 (2021) legalized duplexes on single-family lots statewide and allowed cities to upzone areas near transit; Minneapolis became the first major US city to eliminate single-family zoning citywide through its 2040 Comprehensive Plan; Oregon passed statewide legislation allowing duplexes in all residential zones. The YIMBY movement's core claim — that the primary cause of housing unaffordability is supply restriction — is well-supported by the economic literature.
What housing policies actually work?
The evidence from both economics research and international comparison suggests that housing affordability is most effectively addressed through policies that increase supply, with targeted support for those who cannot afford market-rate housing. Zoning reform — allowing denser development near transit, eliminating parking minimums, legalizing multi-family housing in currently single-family zones — is the most consistently supported intervention in the economic literature. Cities and countries that have maintained permissive zoning regimes have generally maintained better housing affordability. Tokyo is the most striking example: Japan's national zoning law, which limits local governments' ability to impose restrictive zoning, has kept Tokyo's housing costs moderate despite its enormous size and continued population growth. Tokyo adds more new housing units annually than most entire US states. Vienna's model of social housing, in which roughly 60% of residents live in municipally-owned or subsidized housing, demonstrates that public provision at scale can maintain affordability — but requires sustained public investment over decades and political commitment that is difficult to replicate elsewhere. Singapore's Housing Development Board, through which the government provides public housing for approximately 80% of the population, is perhaps the most comprehensive public housing system in the world, maintaining affordability through direct public provision rather than market regulation. The land value tax, proposed by Henry George in 'Progress and Poverty' (1879) and advocated by contemporary economists including Joseph Stiglitz and Paul Romer, taxes the location value of land rather than the buildings on it. Because land value is created by public investment and community activity rather than by the landowner's effort, this tax does not distort productive incentives and creates strong incentives to use land efficiently rather than leave it underdeveloped. Most countries use some version of property tax that includes building value, which taxes development and thereby reduces it.
Why is the US housing market so different from other countries?
The US housing market is distinguished from most other developed countries by the extreme fragmentation of land use regulation, the fiscal incentives that encourage homeownership at the expense of rental housing and new construction, and the historically racial origins of exclusionary zoning. Land use in the US is governed by thousands of local jurisdictions, each with its own zoning code, each responsive to the political pressure of existing property owners. There is no national housing policy in the sense that France, Germany, or the Netherlands has one — no national framework governing what can be built where, no national housing investment program, no meaningful constraints on local governments' ability to prohibit dense development. The result is a patchwork of exclusion: wealthy suburbs surround high-demand job centers, legally prohibiting the density that would enable workers to live near their jobs. California alone has 478 municipalities with independent zoning authority. The fiscal incentives in US housing policy are also unusual. The mortgage interest deduction and the capital gains exclusion on primary residence sales (\(250,000 for individuals, \)500,000 for couples) together represent the largest items of federal housing expenditure — far larger than all social housing subsidies combined — and they disproportionately benefit wealthy homeowners rather than those most in need of affordable housing. Proposition 13 in California, passed in 1978, capped property tax increases at 2% per year regardless of how much home values rose — creating strong incentives for existing homeowners to oppose new development (which would increase congestion and public service demand without generating proportionate property tax revenue) and allowing long-term homeowners to accumulate enormous untaxed equity gains while newer residents pay much higher effective tax rates. Chang-Tai Hsieh and Enrico Moretti's 2019 American Economic Review paper estimated that if New York, San Francisco, and San Jose had maintained median construction elasticity, US GDP would be approximately 9% higher — a $2 trillion annual cost of supply restriction attributable primarily to US-specific zoning fragmentation.