The neighbourhood shop is more expensive, and everybody knows it. A comparison is easy to run. Milk, bread, eggs, detergent: the chain store on the main road undercuts the corner shop by something between twelve and twenty per cent, consistently, across most of the basket. The shopkeeper is not overcharging. He buys in quantities that make his own cost higher than the chain's retail price on several lines. The rational conclusion appears obvious, and a certain kind of commentator draws it with enthusiasm: the small shop is an inefficiency, sustained by sentiment, and its disappearance is the market correcting an error. This account is tidy and, I think, wrong, though not for the reasons usually offered in reply. The defence normally made is nostalgic, and nostalgia is a weak argument because it concedes the economics and asks for an exemption on emotional grounds. A stronger case is available, and it is a case about what is actually being purchased. Consider what the corner shop supplies that does not appear on the receipt. It extends credit, informally, to people whose income arrives irregularly, and it does so without paperwork, interest or a credit assessment. It holds keys. It accepts parcels. It knows which elderly resident has not appeared for two days, and it is frequently the mechanism by which somebody checks. It converts a street of strangers into a set of people who are, at minimum, recognisable to one another. None of this is charity. It is unpriced infrastructure, and its cost is embedded in that twelve to twenty per cent. Once the comparison is stated properly, the arithmetic changes. The chain is cheaper on the basket and silent on everything else. The shop is dearer on the basket and supplies a second category of service that has no separate market and therefore no separate price. The difficulty is that this second category cannot be bought deliberately. Nobody walks in intending to purchase social infrastructure; they buy bread, and the infrastructure is a by-product of enough people buying bread often enough. It is sustained by habit and destroyed by optimisation, one rational decision at a time, each of which is defensible in isolation. Which is the honest shape of the problem. The shop does not close because the neighbourhood stops valuing it. It closes because each individual saves eleven lira, forty times a year, while continuing to believe the shop should remain. It usually remains, until it does not.