Some neighborhoods have several full-service grocery stores and others have none. The pattern follows from how grocery retail operates rather than from whether residents want to buy food.
Grocery margins are thin by design
Supermarkets earn small margins on each item and depend on volume, so a store's viability rests on sales per square foot rather than on the number of nearby residents.
Perishable goods spoil, which means slower turnover directly destroys inventory, and a store with low volume loses money on exactly the fresh categories that define a full-service format.
Chains therefore evaluate sites on projected sales density, and areas with lower spending per household can fail that test even when population is high.
Distribution networks decide what is feasible
Stores are supplied from regional distribution centers on fixed routes, and a location far from an existing route costs more to serve per delivery.
Store size matters too, because a chain's systems, planograms and delivery formats are built around a standard footprint that many urban parcels cannot accommodate.
Loading access is a common constraint. A site without room for a tractor-trailer to maneuver requires smaller, more frequent deliveries, which raises cost per case.
Small stores carry different products for a reason
A convenience store operates on higher margins over lower volume, which favors shelf-stable and packaged goods that do not spoil if they sit.
Fresh produce requires refrigeration, faster turnover and staff time for handling and waste management, all of which are difficult at small scale.
This is why the difference between store formats shows up as a difference in what is available rather than only in price.
Transport converts distance into cost
A household with a car treats a distant supermarket as a routine trip. Without one, the same trip is limited by what can be carried on a bus.
Carrying capacity favors frequent small purchases, which forgoes the lower unit prices of larger packages, so the same items cost more per unit for the household with the least flexibility.
Delivery services change this where they operate, though fees, minimum orders and payment method requirements affect who can actually use them.
What has been tried
Interventions include financing programs for store development, zoning and permitting changes, support for corner stores to stock fresh items, mobile markets and public market halls.
Results have been mixed, and evaluations often find that opening a store changes purchasing less than expected, since price, time and habit continue to operate.
That finding is itself debated, with disagreement about how long an effect should take to appear and what should be measured, so the question remains open rather than settled.