An interesting piece. I was always wondering about the politics and economics behind supermarket location and quality, but cannot find any definite patters.
In a neighborhood I used to live, there was a SuperFresh chain outlet. Superfresh caters mainly to MD suburbs and has a nice store there, but their store in the city was a dump - well-fed cockroaches were running across the floor and the selection was poor. The store eventually close. At the same time, a locally owner small chain nearby prospered, but by catering mainly to students and urban professionals. Several years later, a large Safeway store opened nearby (opposed by local activists on aesthetic grounds) and it had a very positive impact on the surrounding neighborhood, not to mention that it serves predominantly African American community.
Where I currently live (empowermetn zone downtown Baltimore), there are only junk food outlets (of the worst possible quality, such as friend chicken joints - even Burger King pulled out) and a few convenience stores with limited selection and inflated prices. The onwer of one can barely make it and is seeking a liquor licence which most of the community opposes. The city made several efforts to attract a large chain (such as Safeway) to this area, but so far there are no takers. However, within a 10 minute walk an upscale Whole Foods chain opened - they offer decent quality food and good variety. They are a bit pricey, but not so much if you account for the quality of their merchandise - which superior to what Safeway offer, not to mention the convenience joints that offer junk at the same or higher prices.
Interestingly, the housing project residents tend to continue shopping at the convenience joints. Go figure.
Wojtek