School catchment price premium
A Socratic walk-through of the school catchment price premium — reasoned out one step at a time, not lectured.
The question we started with
THE QUESTION #Why does a house in the best catchment cost almost exactly what the school appears to be worth?
Two houses stand on opposite sides of the same street. Same age, same size, same view, same distance to the station. One is inside the catchment of the sought-after school and sells for a great deal more.
The coincidence worth noticing is not that there is a gap. It is how precise the gap tends to be — it lands near what parents in that market appear willing to pay for the school, rather than at some arbitrary figure. Nobody sets it. No estate agent has a formula for what a good school is worth. So the interesting question is not why the school raises prices, but what process makes the increase come to rest at that particular number.
Reasoning it through
REASONING #Start with a state of affairs that cannot last, and ask what happens to it.
Suppose the two houses cost the same today. Then a family who values the school at, say, thirty thousand is being offered thirty thousand pounds of value for nothing. That is a free lunch sitting in plain view of everyone in the market. What does a free lunch do to a price? It attracts bidders. The family bids the price up, another family outbids them, and each of them is still better off than buying across the road.
Now ask the decisive question: when does the bidding stop? Not when the buyers run out of enthusiasm, and not at a figure anyone considers fair. It stops when the gap has grown large enough that the next bidder is indifferent — when the extra cost of being inside the boundary exactly equals what being inside is worth to them. One pound more and they buy across the road instead. This is the whole mechanism: the premium is not set by anyone, it is what remains after every profitable move has been taken.
That reasoning tells us the answer had to look this way. Any smaller premium leaves a gain unclaimed, and someone claims it. Any larger premium means the last buyer overpaid and would rather be outside, so the price falls back. The observed gap is the only figure at which nobody wants to move, which is what an equilibrium is.
It also predicts something we can check. Because the mechanism runs on the boundary, the price should jump sharply at the line rather than fading gently with distance. Two houses metres apart, alike in every other respect, should differ. That comparison is the basis of a well-known research design: Sandra Black's 1999 study compared homes just either side of attendance boundaries precisely so that neighbourhood quality was held roughly constant, and found a clear premium attaching to better-performing schools. Later work in several countries has repeatedly found the same discontinuity, though the size varies with how tightly the boundary actually determines admission.
Now follow two consequences that the tidy story does not advertise.
The first: the school is free and the education is not. A family without the capital to buy in is excluded as effectively as by a fee, except that the fee is invisible, is paid to the previous owner rather than to the school, and appears in no education budget. The state provides the place at no charge; the market re-prices access to it and collects the difference.
The second is more uncomfortable. Part of what makes such a school good is its intake — the prior attainment, resources and involvement of the families in it. But the premium selects that intake, admitting families who could afford the gap. So the price is partly buying the thing it helps create, and the loop closes on itself. This is worth stating carefully rather than dramatically: the size of peer effects relative to teaching quality is genuinely contested, and the honest claim is that the premium capitalises perceived quality, some unknown share of which is the intake the premium itself produced.
One more precision. The gap reflects the marginal buyer, not the average one. Families who value the school far above the premium do exist — they get a real bargain, and it is their good fortune rather than a flaw in the argument. What equilibrium removes is the last available gain, not everyone's surplus. And the adjustment is neither instant nor exact: transaction costs, uncertainty about where boundaries will fall next year, and plain misinformation all leave slack, which is why the pattern is a strong tendency rather than an accounting identity.
The analogy
THE ANALOGY #Think of two adjacent queues at a border crossing, one visibly faster. Nobody manages the queues, yet they end up taking about the same time — because every driver who spots the shorter one joins it, and joining lengthens it. The queues equalise not because anyone balanced them but because any remaining advantage is exactly what people move to capture, and the moving is what destroys it.
switching queues is free, whereas moving house costs a large sum and takes months — so catchment premiums adjust slowly and imperfectly, and unlike a queue they can persist as a permanent barrier to anyone who cannot pay the entry cost at all.
Clarifying the model
THE MODEL #Three refinements.
First, this is not a claim that the school is worth the money. It is a claim that the price reflects what buyers believe it is worth. If a school's reputation lags its actual results by five years, the premium tracks the reputation. The market equalises returns on belief, and beliefs about schools are formed from league tables that measure intake almost as much as teaching.
Second, the premium is a transfer, not a payment for anything. It goes to whoever owned the house before, who did nothing to improve the school. That is why catchment effects show up as a windfall to incumbent owners and are so fiercely defended when boundaries are redrawn.
Third, the argument explains why some remedies fail. Improving a nearby school does not simply help the families near it; it shifts demand, and the premium moves with it. Interventions that leave the boundary rule intact tend to relocate the gap rather than close it, which is part of the case for lotteries or banded admissions that break the link between an address and a place.
A picture of it
THE PICTURE #How to readRead down the page as time. Each bid is individually rational — every bidder is still better off than buying across the road — and each one shrinks the advantage that made bidding worthwhile. The premium is not chosen at any step; it is where the sequence runs out, at the point where the marginal bidder no longer cares which side of the boundary they live on.
What became clearer
WHAT CLEARED #The catchment premium matches what the school appears to be worth because any mismatch is an opportunity, and opportunities in an open market get bid away. Nobody prices the school; the price is simply what is left when every profitable move has been made. The consequence is that a free school ends up rationed by wealth through the housing market — and that the money paid for access goes to a previous homeowner rather than to any child's education.
Where to go next
ONWARD #- Admissions lotteries and banded intakes as attempts to break the address-to-place link.
- Capitalisation more generally: how transport links, flood risk and noise get priced into land.
- School value-added measures, which try to separate teaching quality from the intake it started with.
Key terms
TERMS #| Term | What it means |
|---|---|
| Capitalisation | the process by which the value of a local amenity is absorbed into the price of the land or property that gives access to it. |
| Equilibrium price | the price at which no participant has anything further to gain by moving, so it stops changing. |
| Boundary discontinuity design | comparing outcomes just either side of an administrative line to hold other neighbourhood factors roughly constant. |
Every term the collection defines is gathered in the glossary.