What moves house prices

The mortgage rate is a lever on the price, not a cost beside it

Most buyers do not decide what a home is worth. They decide what they can pay each month, and the prevailing interest rate then converts that monthly figure into a sum of money. This is the single most important mechanical relationship in residential property. Consider the arithmetic: a payment that supports a $400,000 loan at six per cent over thirty years supports roughly $475,000 at five per cent and roughly $340,000 at eight. The buyer's circumstances did not change at all. The price they can bid changed by a third.

This is why rate changes show up in housing so violently and so quickly, and why they show up first in volume rather than price. When rates rise, the immediate effect is not that homes get cheaper; it is that fewer homes sell, because sellers with a low fixed rate on their existing loan decline to move and buyers withdraw. The market thins from both sides at once.

Incomes set the ceiling

Rates decide how much of an income can be turned into borrowing; incomes decide how much income there is. Over long periods local prices track local earnings reasonably closely, because a place cannot indefinitely charge more for shelter than the people who work there can pay for it. Divergences happen, and they persist for years, but they generally have an identifiable source: buyers whose income is earned elsewhere, purchases made with capital rather than earnings, or a genuine change in the quality of what the area offers.

Travel time, not distance

Land value in any city is largely a map of how long it takes to get somewhere else. Distance in miles matters much less than distance in minutes, which is why two blocks either side of a subway station can differ in price, and why an outlying area with a fast express train can be dearer than a closer one on a slow local. It also means transport decisions are housing decisions. A new station, a new service pattern, a bridge toll, even a change in timetable, revalues everything within walking distance of it.

Costs that ride alongside the mortgage

A buyer's monthly capacity is finite and everything charged monthly competes for it. Property tax, maintenance or common charges, insurance, and in some buildings an underlying mortgage on the corporation are all paid from the same pocket as the loan. A dwelling with high monthly charges is therefore worth less, other things equal, than an identical dwelling with low ones, and the difference is roughly the capitalised value of the gap. This effect is large and consistently underestimated by people comparing headline prices between buildings.

Things that look like causes and are not

Several popular explanations describe symptoms. 'Low inventory' is usually the result of price movement rather than its cause, since owners list when they expect to sell well. 'Demand from buyers' is not an explanation unless you can say where the money came from. And the arrival of a particular kind of shop is a lagging indicator of a change in the local population, not the reason for it. When you look for a cause, look for something that changed the amount of money able to reach the area, or the number of homes it can be spent on.

Direction is knowable, timing is not

The forces above can be reasoned about. The moment at which they express themselves in transacted prices cannot, because that depends on the willingness of individual owners to accept an offer, which is a matter of private circumstance. Analysis in housing is honest when it describes mechanisms and candid when it declines to forecast dates.