Housing & homelessness
Homelessness, housing supply and support. Real interventions, each with its sources: what worked, what didn't, and why.
11 worked6 mixed2 didn't work
What worked
- WorkedHousing & homelessness
Housing First: ending long-term homelessness in Finland
ChallengeA core group of long-term homeless people kept cycling through shelters, hospitals and jails.
A permanent home with a lease first, support services second.
−68%long-term homelessness, 2008–2022ObservationalRead case - WorkedHousing & homelessness
Vienna's social housing
ChallengeCities struggle to keep housing affordable for working and middle-class residents.
A city where around half of residents live in municipal or subsidized housing.
~50%of residents live in social or subsidized housingObservationalRead case - WorkedHousing & homelessness
Singapore's public housing (HDB)
ChallengeSingapore faced severe slums and overcrowding after independence.
Government-built flats sold on long leases, now home to most Singaporeans.
76.0%of Singapore residents live in HDB flats (2024/25)ObservationalRead case - WorkedHousing & homelessness
Houston's coordinated Housing First system
ChallengeHouston had one of the largest homeless populations in the US and a fragmented system of providers.
Dozens of agencies working as one system to move people straight into housing.
−61%homelessness in the region, 2011–2023ObservationalRead case - WorkedHousing & homelessness
Auckland's citywide upzoning
ChallengeAuckland had a severe housing shortage and some of the world's least affordable homes.
Allowing townhouses and apartments across three-quarters of the city's residential land.
21,808extra homes permitted in five years after upzoningQuasi-experimentalRead case - WorkedHousing & homelessness
California's backyard home (ADU) reforms
ChallengeCalifornia had a deep housing shortage, and local rules blocked even small new homes.
State laws forcing cities to allow small second homes on single-family lots.
5,911 → 15,571ADU permits statewide, 2018 to 2019ObservationalRead case - WorkedHousing & homelessness
Houston's minimum lot size reform
ChallengeLarge minimum lot sizes kept new, more affordable homes from being built in central Houston.
Shrinking the minimum lot size so townhouses could be built on land meant for one house.
5,000 → 1,400square feet minimum lot sizeObservationalRead case - WorkedHousing & homelessness
Tokyo's permissive zoning and steady housing supply
ChallengeBig cities struggle to build enough homes to keep up with demand.
National zoning rules that let a megacity keep building, keeping rents stable.
129,571new homes started in Tokyo, fiscal 2024 (April 2024–March 2025)ObservationalRead case - WorkedHousing & homelessness
Champlain Housing Trust: a community land trust
ChallengeRising home prices were putting homeownership out of reach for working families.
A nonprofit owns the land so homes stay affordable for every future buyer.
3,000+permanently affordable homesObservationalRead case - WorkedHousing & homelessness
Montgomery County's inclusionary zoning (MPDU)
ChallengeNew suburban development was producing homes only wealthier families could afford.
Requiring new developments to include affordable homes, scattered across wealthy suburbs.
15,000+affordable homes producedQuasi-experimentalRead case - WorkedHousing & homelessness
Atlanta's shipping container housing (The Melody)
ChallengeMany chronically homeless people avoided shelters because of restrictive rules.
Fast, low-cost homes for chronically homeless people, built from shipping containers.
30%lower construction cost per bed than traditional shelters, across the container model's three citiesObservationalRead case
Mixed results
- MixedHousing & homelessness
Moving to Opportunity
ChallengeFamilies in high-poverty public housing had few routes to better neighborhoods.
Housing vouchers to help families in high-poverty public housing move to better neighborhoods.
+31%adult earnings for children who moved youngRCTRead case - MixedHousing & homelessness
Utah's 91% claim on chronic homelessness
ChallengeChronically homeless people were costly to public services and hard to house.
A celebrated Housing First success story that turned out to rest partly on counting changes.
−91%?claimed fall, later found inaccurate by a state auditObservationalRead case - MixedHousing & homelessness
Minneapolis 2040: ending single-family-only zoning
ChallengeRents were rising and most residential land allowed only single-family homes.
The first major US city to allow duplexes and triplexes on every residential lot.
17.5–34%lower rents than a counterfactual, likely due mainly to weaker demandQuasi-experimentalRead case - MixedHousing & homelessness
San Francisco's rent control expansion
ChallengeRising rents threatened to push long-term tenants out of San Francisco.
Extending rent control to small older apartment buildings in 1994.
−15%rental supply in covered buildingsQuasi-experimentalRead case - MixedHousing & homelessness
Vancouver's foreign buyer tax
ChallengeMetro Vancouver home prices were soaring, and foreign buyers were blamed.
A 15% extra tax on homes bought by foreign nationals in Metro Vancouver.
13.2% → 1.3%foreign buyers' share of Metro Vancouver home transfers, before vs after tax, 2016Quasi-experimentalRead case - MixedHousing & homelessness
DAHLIA affordable housing portal: San Francisco
ChallengeEach building had its own paper forms, queues and lotteries, making affordable housing hard to find and apply for.
Replaced scattered paper applications with one city website to search and apply for affordable housing.
97%share of San Francisco affordable housing applications made through DAHLIA, May 2021ObservationalRead case
What didn't work
- Didn't workHousing & homelessness
Pruitt-Igoe public housing in St. Louis
ChallengeSt. Louis needed modern, decent housing for low-income families after clearing slums.
A modernist high-rise housing project, demolished less than 20 years after it opened.
1954–1972from opening to the start of demolitionObservationalRead case - Didn't workHousing & homelessness
Berlin's rent cap (Mietendeckel)
ChallengeRents in Berlin were rising fast and tenants feared being priced out.
A five-year freeze on rents for about 1.5 million apartments.
Up to 60%drop in Berlin rental listings attributed to the cap (ifo)Quasi-experimentalRead case