Brad DeLong has a long post about the benefit of having the choice of shopping at CostCo versus not having the choice. The alternative being Western Europe, where a lack of CostCo type places or large supermarkets force many consumers to purchase their, for example, meat at high cost boutique butcher shops.
What DeLong doesn't realize is he's making the argument that many critics of Walmart make, but in reverse. When Walmart hits an isolated small town, driving the local shops out of business, is it a good or a bad thing? Well, for people who would prefer to shop at Walmart it is a good thing. For the people who would prefer to shop in the now derelict town square, it is a bad thing.
No Costco/Walmart limits peoples choices, but often so does their presence.
