Housing and Communities: what the evidence shows

The evidence on Housing and Communities in the United States is clear that housing has become more expensive relative to income: the national home price-to-income ratio was 5.0 in 2024, and a record 22.6 million renter households were cost burdened in 2023, according to Harvard’s Joint Center for Housing Studies. Research is strong on some specific questions, such as what a rent control expansion did in San Francisco, and contested on others, such as how much zoning raises prices nationally and why homelessness rose. Much of what voters most want to know, including which mix of policies would lower costs fastest without harming existing residents, is not settled.

In plain words

Some housing facts are well measured. We know roughly how many renters pay more than 30% of their income for housing, how many people own their homes, and how many people were counted as homeless on one night in January.

Other questions are harder. Does building more homes lower rents for lower-income families, and how quickly? Do rent limits help or hurt renters over time? Why did homelessness rise so much? Good studies exist, but they often study one city or one period, and people draw different lessons from them.

This page sets out what is known, where researchers disagree, and what nobody knows yet. It is a companion to the main Housing and Communities page and the Who decides page.

Defined terms

Cost-burdened household. A household spending more than 30% of income on housing and utilities. Severely cost-burdened means more than 50%.

Price-to-income ratio. Median home price divided by median household income.

Rental vacancy rate. The share of rental housing units that are vacant and available for rent.

Housing starts and completions. New housing units on which construction began, or was finished, in a period.

Chronic homelessness. As the Joint Center summarizes it, being unhoused for at least a year or experiencing episodic homelessness during the last three years.⁠¹

Housing First. An approach that houses people first and then provides supportive services for needs such as mental health or substance use.⁠¹

Evidence on housing costs

The Joint Center for Housing Studies of Harvard University reports that for the third consecutive year the number of cost-burdened renters reached a record in 2023: 22.6 million renter households, or 50% of renters.⁠¹ Of these, more than 12.1 million (27% of renters) were severely burdened, spending more than half their income on housing and utilities.⁠¹

Owners are also affected. As of 2023, the Joint Center reports, 24% of homeowners were cost burdened, and the number of burdened owner households rose by 646,000 that year to 20.3 million.⁠¹ The national price-to-income ratio for homes reached 5.0 in 2024, on par with the 2022 record and above the 4.1 of 2019.⁠¹

Measurement caution. The 30% threshold is a convention. A high-income household spending 35% of income on housing may be comfortable; a low-income household spending 25% may not be. Cost-burden counts also do not capture people who have doubled up or moved far away to find lower costs.

Housing supply and vacancy: what the data show

The Census Bureau reported a national rental vacancy rate of 7.3% and a homeowner vacancy rate of 1.2% in the second quarter of 2026, with a homeownership rate of 65.0%.⁠²

Construction has swung sharply. The Joint Center reports that developers completed 608,000 multifamily units in 2024, the most in nearly four decades and more than double the 298,000 averaged annually since 1990.⁠¹ Multifamily starts, however, fell 25% to 354,000 units in 2024, 35% below the 2022 peak of 547,000.⁠¹ For existing homes, the number available for sale rose 20% year over year to 1.33 million in March 2025, but remained 27% below the 1.82 million averaged in that month in earlier years, according to National Association of Realtors data cited by the Joint Center.⁠¹

Interpretation. A wave of new apartments can raise vacancy and slow rent growth in the markets where it lands, and the Joint Center links the 2024 completions to moderating rent growth.⁠¹ Whether that relief reaches lower-income renters, and how long it lasts as starts fall, is a central question for the next few years.

Homelessness: what the data show

The Joint Center, citing HUD’s point-in-time count, reports that 771,480 people were homeless in January 2024, a 33% increase since January 2020, and that an all-time high of 152,590 people were chronically homeless.⁠¹ It attributes part of the rise to a temporary surge in asylum seekers and much of it to growing housing costs and a lack of affordable housing.⁠¹

Measurement caution. A count taken on a single night in January cannot see everyone. Unsheltered people are hard to find, local counting methods can differ, and one night misses people who cycle in and out of homelessness. Counts are best used for trends within the same community over time, not precise national totals.

Where researchers disagree: zoning and supply

Researchers broadly agree that regulation affects housing costs, but disagree about how much and where.

Glaeser and Gyourko argue that in many U.S. markets the gap between home prices and construction costs acts as “a regulatory tax,” and that the evidence points toward, though does not conclusively establish, that this tax exceeds any reasonable estimate of the costs new building imposes on neighbors.⁠³ They also argue that high prices in productive regions reduce workers’ ability to move to higher-wage areas.⁠³

Critics and skeptics raise several points. Some argue that in the highest-demand areas, new market-rate housing mainly serves higher-income households and takes years to affect what lower-income renters pay. Others argue that land costs, interest rates, construction labor and materials matter as much as zoning. Still others argue that the value of neighborhood stability and local preferences is undercounted in economic models. These disagreements explain why zoning reform has supporters and opponents in both parties.

States are now running the experiment. Oregon’s 2019 law requiring cities to allow duplexes and middle housing,⁠⁴ and the 14 states that the Joint Center says now preempt local limits on accessory dwelling units,⁠¹ will generate evidence over the coming decade. It is too early to measure their full effects.

Where researchers disagree: rent regulation

Rent regulation has been studied closely, and the best-known recent study shows effects in both directions. Diamond, McQuade and Qian studied an expansion of rent control in San Francisco and found that it limited renters’ mobility by 20% and lowered displacement from the city, while treated landlords reduced rental housing supply by 15%, mainly by converting to owner-occupied housing or redeveloping, which the authors say likely drove up market rents in the long run.⁠⁵

How to read it. Tenant advocates emphasize the first finding: rent control did what it was meant to do for covered tenants. Critics emphasize the second: it shrank the rental stock. Both readings use the same study. Whether the tradeoff is worth it depends on how one weighs current tenants against future renters, and the results of one city’s specific policy may not generalize to different designs, such as rent stabilization with vacancy decontrol or caps tied to inflation.

Where researchers disagree: homelessness responses

Responses to homelessness are debated as much on values as on evidence. The Joint Center notes that some places, including Houston and Milwaukee County, have reduced homelessness using housing first principles, housing people first and then providing services such as mental health and substance use treatment.⁠¹ Critics of housing first argue that it can deprioritize treatment and that results vary by place and population. Supporters of greater enforcement against encampments, an option the Supreme Court left open to local governments in 2024,⁠⁶ argue that it protects public spaces and moves people toward services; opponents argue that it moves people without housing them. Rigorous comparisons across these approaches remain limited.

Comparative evidence

International comparisons show that housing systems differ in structure, not just in policy. Vienna reports about 220,000 municipal flats and about 200,000 subsidized cooperative flats, with around half of residents living in subsidized dwellings.⁠⁷ Supporters of social housing cite Vienna as evidence that large public and nonprofit housing sectors can provide stable housing across income groups. Skeptics note that Vienna’s system was built over a century under different law, land and financing conditions, and that cost comparisons across countries are difficult. Neither side can simply transplant the evidence to a U.S. city.

What is unknown about housing and communities

• The full effect of state zoning preemption on prices, rents and construction, since most reforms are recent.
• How fast new market-rate supply reaches lower-income renters through vacancy chains in different markets.
• The precise causes of the rise in homelessness since 2020, and how much each factor contributed.
• The long-run effects of different tenant protections, including right-to-counsel and eviction diversion, beyond the places studied.
• How housing costs shape community life, such as civic participation and local services, which is hard to measure.

Competing interpretations

A scarcity interpretation holds that the core problem is too few homes where people want to live, pointing to the price-to-income ratio.⁠¹ and the regulatory tax argument⁠³

A distribution interpretation holds that the core problem is incomes and power, pointing to record renter cost burdens⁠¹ and the vulnerability of tenants to displacement.

A place interpretation holds that national data mislead, because the housing problem in a booming metro is the opposite of the problem in a shrinking town, and evidence should be read locally.

These interpretations are not exclusive. They lead to different first steps, which is why the same evidence supports different proposals.

Application to this framework

• My Vote Forward presents housing evidence next to participants’ priorities, so discussion can start from dated, sourced facts. See Priorities.
• Evidence does not settle the values question at the center of housing: how to weigh current residents against future ones, and renters against owners. See Tradeoffs.
• Numbers carry dates, denominators and sources so they can be checked and updated. See Measurement.
• When a specific housing proposal is discussed, its own evidence should be labeled as data, research or interpretation. See Proposals.

Unresolved questions

• How should a public resource present studies like the San Francisco rent control paper, which supports opposite conclusions depending on whose interests are weighed?
• Which housing outcomes (rents, ownership, displacement, homelessness, segregation) should be tracked when communities compare proposals, and who decides?
• How can local housing evidence be presented for small places without exposing individual households? See Collective priorities.
• How should evidence pages flag that the main reforms of the 2020s are too recent to evaluate?