Why You Can't Afford a House: The Real Economics Explained

The Housing Affordability Crisis Is Not an Accident

In early 2021, a derelict three-bedroom property in Auckland — boarded-up windows, peeling paint, functionally uninhabitable — sold for NZ$1.81 million. The New Zealand press called it a "dunger," local slang for something barely holding together. Buyers called it a wise investment. At the peak of the market in early 2022, the average Auckland home cost roughly NZ$1.4 million, or approximately 35 times the median annual income. That is not a rounding error. That is a system working exactly as designed.

The housing affordability crisis gripping most of the developed world — the United States, United Kingdom, Canada, Australia, and New Zealand among them — is not a market failure in the traditional sense. It is the predictable output of decades of deliberate policy choices, interest rate mechanics, and political calculus that consistently favours existing homeowners over prospective buyers. Understanding why you can't afford a house requires looking at all three.

The Interest Rate Engine That Drove 40 Years of Price Growth

Most buyers don't think in terms of total purchase price. They think in monthly payments. This one behavioural fact explains more about house price inflation than almost anything else.

Consider a buyer with $1,500 a month to spend on a mortgage. Here's what that monthly budget could actually purchase across different rate environments:

• 1981 (rates ~20%): approximately $90,000 in borrowing capacity
• January 2021 (rates ~2.65%): approximately $370,000 in borrowing capacity
• Today (rates ~6.5%): approximately $236,000 in borrowing capacity

Same buyer. Same monthly budget. Wildly different purchasing power depending on the decade. The entire 40-year run-up in residential property prices in the developed world tracks almost perfectly with the secular decline in interest rates from the early 1980s onwards.

This is not coincidence. Lower rates mechanically expand how much debt a fixed income stream can service, and in competitive housing markets, buyers bid up to the limit of what they can afford. Every time central banks cut rates, the ceiling on home prices rose — not because homes became more valuable in any productive sense, but because the same monthly cash flow could support a larger loan.

What this also means is that the reversal of that trend is painful in both directions. A buyer who locked in a 2.65% 30-year fixed mortgage in 2021 — a uniquely American product, it should be noted — has almost no incentive to sell. They'd have to surrender a historically cheap mortgage and replace it with one at 6.5%, slashing their purchasing power by roughly a third. The result is a frozen market: existing homeowners stay put, inventory stays scarce, and prices resist the downward correction that affordability math would otherwise demand.

In countries like New Zealand, where fixed-rate periods are short or mortgages float entirely, there is no such cushion. When rates rose, monthly payments rose immediately. Homeowners who stretched to buy at peak prices faced a stark choice: find more cash, renegotiate, or sell. Over 2,000 construction firms in New Zealand have gone insolvent since 2022, and property prices have fallen 16% nationally — 27% in Wellington — from their peaks. Adjusted for inflation, real values are down closer to a third.

The Political Architecture of Expensive Housing

Here is the uncomfortable arithmetic that drives housing policy in most democracies: homeowners vote in higher proportions than renters, older voters turn out more reliably than younger ones, and the largest asset most households will ever own is their home. Any politician who allows house prices to fall is making their most reliable constituency poorer and angrier. Any politician who keeps prices rising is making them feel wealthy.

Framed that way, the policy choices across the past four decades make complete sense — not as good economics, but as rational political strategy.

Governments across the developed world have consistently deployed a toolkit of measures that are publicly announced as affordability solutions but function in practice as demand stimulants:

• First-home buyer grants: These rarely help buyers afford homes. They help buyers bid more for the same homes, transferring the subsidy directly to sellers.
• Mortgage interest tax relief: A subsidy to borrowing that disproportionately benefits those who can already access large loans.
• Landlord tax breaks: Incentivises capital allocation into existing housing stock rather than productive investment, inflating asset prices further.
• Planning restrictions: Making it genuinely difficult to build new housing constrains supply regardless of how hot demand gets.

Each instrument, individually, has a defensible rationale. Together, they constitute a coordinated policy of price support for an asset class that a significant share of the population cannot access at all.

The UK is an instructive case. The Town and Country Planning Act of 1947 effectively nationalised development rights and established green belts around major cities. Successive governments have announced targets of 300,000 new homes per year for decades. They have consistently missed them. The result: flat prices in London have fallen roughly 5.5% since January 2020, while house prices have risen over 10%. The so-called property ladder — buy a flat, let it appreciate, trade up to a house — has become, as one analyst put it, a game of property snakes and ladders. The rung that was supposed to lift millennials into family homes has quietly been removed.

Land Value vs. Real Wealth: A 19th-Century Insight That Still Cuts

The distinction between productive wealth creation and land appreciation is one that most housing market commentary glosses over. It shouldn't.

When you invest in a business, capital flows toward activity: manufacturing, service delivery, product development, employment. The economy grows in a measurable way. When you buy a house, the physical structure does nothing productive and actually depreciates — roofs need replacing, plumbing corrodes, kitchens go out of fashion. The only component that appreciates is the land.

An American political economist named Henry George made this precise observation in 1879 in a book called Progress and Poverty, which was, improbably, one of the best-selling books in the United States at the time. George's argument: land increases in value not because of anything the owner does, but because of what the surrounding community does. A new train station, a good school, a major employer moving nearby — these are the forces that lift land values. The owner simply collects the windfall.

His proposed solution — a single tax on land value, replacing taxes on labour and capital — has attracted support from economists across the political spectrum ever since. The logic is elegant: taxing wages discourages work; taxing factories discourages investment; taxing land discourages nothing, because land doesn't respond to incentives. It just sits there.

Whether a land value tax is practically implementable at scale is a genuinely complex question. But George's core observation stands up well: when house prices rise, the wealth being created is largely illusory at the national level. If you buy a house for $300,000 and sell it a decade later for $800,000, you haven't generated $500,000 of new economic value. The buyer has simply had to borrow an additional $500,000 from a bank. If you need to buy a replacement home, it has likely also increased in price. The net effect at a societal level is a large-scale transfer of capital from younger buyers — who need somewhere to live — to older sellers — who happened to buy 30 years ago. The country is no more productive. The distribution of wealth has simply shifted.

The Supply Side: Why Building More Is Harder Than It Sounds

The obvious fix to a housing shortage is to build more housing. The political economy of doing so is considerably less straightforward.

In Auckland, city officials recently scaled back plans that would have allowed higher-density development in wealthier suburbs. Homeowners already nervous about falling values were unwilling to accept the additional downward pressure of new townhouses nearby. In California, following the wildfires that destroyed thousands of homes, state executive orders offered expedited permits for rebuilding — a sensible intervention in a state with a severe housing shortage. The catch: the fast-track applied only if homeowners rebuilt essentially the same structure on the same footprint, with an allowance of roughly 10% additional size. The crisis became an opportunity to reconstruct the past rather than address the future.

This pattern repeats across the developed world. Construction booms happen when prices are rising and developers are profitable. When prices fall, construction firms go insolvent — over 2,000 have in New Zealand since 2022 — and the pipeline of new supply dries up precisely when affordability most needs it. Governments, meanwhile, face no electoral incentive to stimulate new supply when doing so would further depress the asset values of existing homeowners.

The result is a structural undersupply that persists across multiple economic cycles, keeping a floor under prices even when all the fundamentals suggest they should correct sharply.

What Elevated Rates Mean for Property Markets Going Forward

For four decades, central bankers operated with significant structural tailwinds. Globalisation suppressed the price of goods. Favourable demographics — large working-age populations relative to retirees — kept wage growth moderate and consumption patterns predictable. Central banks could cut rates repeatedly without triggering sustained consumer price inflation. The property boom was, in part, a side effect of this unusually benign monetary environment.

That environment has materially changed. Demographics have reversed across most of the developed world. Globalisation is fracturing under the pressure of trade policy shifts and geopolitical realignment. Energy markets remain vulnerable to supply shocks — the kind that force central banks to prioritise their inflation mandates over any concern for asset prices.

A central bank cannot calibrate interest rates to protect suburban home values while consumer prices are rising. If keeping rates elevated is what the inflation picture demands, the property market absorbs the consequences. The data suggests that in rate-sensitive markets — those without long-term fixed mortgage products — that absorption has already begun. In markets insulated by locked-in low-rate mortgages, the adjustment is slower but the underlying pressure is the same.

For prospective buyers, the picture is nuanced. Lower prices don't automatically mean better affordability when higher rates reduce borrowing capacity. The monthly payment math doesn't necessarily improve just because the sticker price falls. What changes is the long-term cost of ownership and the size of the deposit required. In markets where prices have corrected 15-25% from peak in real terms, buyers with equity or savings are in a structurally better position than they were at the 2021-2022 peak — even if the headlines suggest otherwise.

Conclusion: Who the Housing Market Actually Serves

The housing affordability crisis is, at its root, a story about whose interests the system was built to serve. The answer, based on the policy record across the developed world, is primarily existing homeowners — a group that overlaps closely with older, higher-turnout voters.

This doesn't mean nothing can change. Several key variables are shifting simultaneously: the interest rate environment is structurally higher than the 2010s, the political salience of housing costs among younger voters is rising, and in some jurisdictions, zoning reform is beginning to gain traction. New Zealand, for all its current pain, has implemented some of the most ambitious density reforms in the developed world over the past five years — and the construction industry is there partly because of how sharp the subsequent downturn was.

The takeaways for financially-minded readers are blunt:

• Housing is not a productive investment in the economic sense. Land appreciation transfers wealth; it doesn't create it.
• Affordability is primarily a function of rates and supply, not price levels alone. A 20% price cut offset by a 2% rate increase may leave monthly costs unchanged.
• The political incentive to support prices is durable but not infinite. Generational shifts in voter composition are beginning to alter the calculus in some markets.
• Construction cycles lag price cycles. When the next downturn materialises, the builders who would solve the supply problem are often already insolvent.

Understanding the mechanics doesn't make buying a home easier. But it does clarify that the difficulty is structural, not personal — and that the system producing these outcomes was, largely, designed to produce them.

---

This article is for informational purposes only and does not constitute financial advice. Always consult a qualified financial professional before making investment decisions.

Frequently Asked Questions

Why do house prices keep rising even when they seem unaffordable? House prices are primarily driven by borrowing capacity, not nominal income levels. When interest rates fall, the same monthly payment supports a larger mortgage, so buyers bid more for the same properties. Simultaneously, supply constraints — planning restrictions, low construction rates, and NIMBYism — prevent the market from responding to demand in the way a normal goods market would. The result is structurally elevated prices even when they appear objectively unaffordable relative to income.

Is buying a house a good investment? The physical structure of a house depreciates over time and requires ongoing maintenance expenditure. The component that appreciates is the land, and that appreciation reflects community investment — infrastructure, schools, employers — rather than anything the owner does. At the national level, rising house prices represent a transfer of wealth from buyers to sellers, not genuine economic value creation. Whether buying makes financial sense depends on your local market, rate environment, time horizon, and the rent-versus-buy calculation in your specific situation. Treating a primary residence as a primary investment vehicle carries concentration risk that diversified asset allocation does not.

Why don't governments just build more houses to solve the shortage? Governments face a structural political disincentive to aggressively expand housing supply, because doing so would exert downward pressure on the asset values of existing homeowners — who vote in higher proportions and are more reliably engaged in the electoral process than renters or non-owners. Planning systems in most developed countries were also designed, often explicitly, to restrict density and protect neighbourhood character, which in practice means protecting incumbent property values. Construction also tends to collapse during downturns, when affordability most needs relief, because developers become insolvent when prices fall.

What happens to house prices when interest rates rise? Rising interest rates directly reduce borrowing capacity. A buyer with a fixed monthly budget can support a smaller loan at a higher rate, which mechanically limits how much they can bid for a property. In markets without long-term fixed-rate mortgages — most countries outside the United States — rising rates also increase existing owners' monthly payments, forcing some to sell. Both effects push prices down. However, lower prices don't automatically improve affordability, because the higher rate increases the total cost of borrowing. A home that is 20% cheaper at a rate 2 percentage points higher may cost the buyer roughly the same in monthly terms.

What is a land value tax and why do economists support it? A land value tax (LVT) is a levy on the unimproved value of land, excluding any structures built on it. Economists across the political spectrum — from libertarians to progressives — tend to view it favourably because, unlike taxes on labour or capital, it does not distort economic behaviour. Land cannot be moved, hidden, or produced in response to a tax. The theoretical case, first articulated systematically by Henry George in 1879, is that taxing land captures value created by the community — infrastructure, amenity, proximity to employment — rather than by the landowner, and redirects it to public use without discouraging productive activity. Practical implementation challenges, including valuation complexity and transitional disruption for asset-rich, income-poor homeowners, have limited its adoption despite its theoretical appeal.