OtterKnow Kids Encyclopedia

Supply and Demand

The most basic explanation for high housing costs is supply and demand. When many people want something and there isn’t enough of it to go around, the price rises. Housing is no different.

The San Francisco Bay Area is a clear example. Over the past several decades, technology companies like Google, Apple, Meta, and thousands of smaller startups have created millions of well-paying jobs in a relatively small geographic area. People who take those jobs need somewhere to live. But the number of new homes built in the Bay Area has not kept pace with the number of new residents. The result: far more people competing for roughly the same number of homes, pushing prices up year after year.

The Value of Land

A house actually has two parts: the building and the land it sits on. The building — the walls, roof, appliances, and fixtures — tends to wear out and lose value over time. But the land underneath is different. Land does not wear out. And in a desirable location, land can become dramatically more valuable as the surrounding city grows.

Here is the key insight: when a neighborhood becomes sought-after, the land in that neighborhood rises in value — even if the owner of the land does nothing at all. The value comes not from anything the owner did, but from the growth of the surrounding community: new businesses opening, new transit lines being built, more families wanting to live there. Economists call this “unearned increment” — value that accrues to a landowner simply because of where the land is, not because of any effort or investment.

This is why two identical houses can have wildly different prices: one in a desirable location near jobs and transit, one in a less connected area. The buildings might be the same. The land value is not.

Zoning and Building Rules

Cities control what can be built where through rules called zoning. Zoning laws divide a city into zones — areas where only houses can be built, areas where apartments are allowed, areas where businesses can operate, and so on.

Many American cities and suburbs have large areas zoned exclusively for single-family homes — meaning only one house can sit on each lot, no apartments allowed. These rules were often put in place decades ago when cities were smaller. Today, they limit how many homes can be built in popular, high-demand areas. When fewer homes are built than people need, prices stay high.

Some people argue that these zoning rules are the main cause of the housing crisis, because they prevent cities from building enough homes near jobs and transit. Others argue that neighborhoods have a right to limit growth to preserve their character, or that more development doesn’t always lead to lower prices. It’s an ongoing debate in cities across the country.

More Homes, Lower Prices

One argument that many economists, city planners, and housing advocates make is that building more homes — especially apartments and multi-family buildings near jobs and transit — is the most effective way to make housing more affordable over time.

The logic: if more homes are available than there are people competing for them, landlords and sellers have to keep prices competitive. If supply can keep up with demand, prices stabilize. Some cities have tested this idea with results worth studying. Tokyo, Japan, for example, has long allowed dense residential buildings throughout the city, including right next to transit stations. As a result, Tokyo has far more stable rents than comparable global cities, even as it is one of the world’s largest metropolitan areas.

What Cities Are Trying

Cities and states are trying a range of approaches to address high housing costs:

• Upzoning: changing zoning rules to allow denser construction in more areas, so more homes can be built near jobs and transit
• Affordable housing requirements: requiring developers who build new apartments to reserve some units at lower rents
• Rent control: laws that limit how much a landlord can raise rent each year
• Land value taxation: taxing the value of land more heavily than buildings, so it is less profitable to hold idle land and wait for prices to rise

Each approach has supporters and critics, and no single policy has solved the problem on its own. Housing affordability is a genuinely hard challenge — one that involves economics, politics, community values, and history all at once.

Fun Facts

• The median home price in the San Francisco Bay Area has exceeded $1 million in recent years — more than three times the national median.
• Tokyo, despite being one of the world’s largest cities, has more stable housing costs than comparable cities partly because it allows dense construction throughout the metropolitan area.
• In 1950, the average American family spent about 20–25% of their income on housing. Today, many families in high-cost cities spend 40–50% or more.
• The original version of Monopoly — called “The Landlord’s Game” — was invented in 1903 specifically to show how landowners profit from rising land values while renters struggle. The game was meant to teach Henry George’s economic ideas.