Housing

Several properties distinguish it from ordinary commodities and explain most of what follows.

It is immobile. A dwelling cannot be moved to where demand is, so location is inseparable from the good and prices vary enormously over short distances.

It is durable. Buildings last for many decades, so the existing stock overwhelmingly exceeds annual construction, and new building changes total supply slowly.

It is expensive relative to income, which means most purchases are financed by debt, and housing markets are therefore also credit markets.

Supply responds slowly. Land assembly, permission and construction take years, so a demand increase raises prices long before it raises output.

It is both consumption and investment. The same object provides shelter and stores wealth, and those two functions pull in opposite directions: rising prices benefit owners and harm those seeking to buy or rent.

Construction costs vary less between places than prices do. The difference is land, and land value is determined by what may be built and by access to employment and services.

Regulatory constraint on what may be built is therefore a principal determinant of price where demand is high, as the zoning capsule sets out. Research consistently attributes a substantial share of housing cost growth in high-demand cities to supply restriction.

Credit conditions matter as much as supply. Because most purchases are financed, interest rates and lending standards affect what buyers can pay, and easier credit is capitalised into prices rather than improving affordability.

Taxation shapes outcomes, and treatment of owner-occupied housing is favourable in many countries, which encourages ownership and inflates prices.

Speculation and investment demand add to occupier demand, and in several cities purchases by investors, including from abroad, form a substantial share of transactions.

Owner-occupation is the dominant aspiration in many countries and is promoted by policy. It provides security of tenure and a savings mechanism, ties households to a location, and concentrates household wealth in a single undiversified asset.

Private renting provides flexibility and, in weakly regulated markets, insecurity. Security of tenure varies enormously between countries, and long-term renting is normal and stable in Germany and Switzerland while being associated with precarity elsewhere.

Social and public housing is provided below market cost by states or non-profit bodies. Its share varies from very large to negligible between countries, and the difference is a policy choice rather than an economic constraint. Vienna's substantial municipal housing sector is the most cited example of a large programme sustained over a century.

Cooperative and community land trust models separate ownership of land from ownership of the dwelling, which removes land appreciation from the price and is used to maintain permanent affordability.

Informal settlement houses a large share of the urban population in many countries, as the urbanisation capsule describes, and secure tenure is the variable most associated with whether residents improve their dwellings.

The disagreement is genuine and the evidence is stronger on some questions than others.

Supply expansion is supported by a substantial body of evidence at the metropolitan level, with new construction associated with lower rent growth. Its effects at the immediate neighbourhood level are more contested, since new development can be associated with rising local prices even while reducing them regionally.

Rent control has a large literature. The general finding is that it protects existing tenants, and that stringent forms reduce the supply and quality of rental housing over time, with second-generation systems permitting increases between tenancies performing differently from strict caps.

Subsidies to demand, including grants to buyers, tend to be capitalised into prices where supply is constrained, which transfers the benefit to sellers.

Social housing construction increases supply directly and requires sustained public expenditure, and the decline in such programmes across several countries from the 1980s coincides with the affordability problems that followed.

Vacancy and second-home taxes address a specific problem in particular markets and are not a general solution.

The recurring finding is that affordability problems are local and structural, and that measures addressing demand without addressing supply raise prices.

Housing costs are the largest single expense for most households, and housing wealth is the largest asset for most owners, which makes housing policy simultaneously a question about living standards and about the distribution of wealth.

The conflict between the two roles is the central difficulty. Policies that make housing cheaper reduce the wealth of existing owners, who are numerous and vote, which is why the problem persists in so many countries despite being well understood.