For thousands of us who walk home from work, our supermarket is a place where we stop and shop, daily. We chat to our friends there, and to the staff, as we do when we meet them in street or pub. Our students get jobs there at weekends and holidays. It is our neighbourhood shop.
Doubtless it is picturesque to stomp round street markets in the rain making lots of individual purchases of usually inferior goods, and then to have to go to a range of small shops to obtain all the things that aren't sold in street markets. But the bulk of us use supermarkets.
A street market of comparable volume to even a small supermarket must also be more expensive to the taxpayer, in terms of policing costs, the supervision of hygiene and trading standards, and in the removal of refuse. I doubt that it would benefit the community by providing jobs in the way that Professor Lang suggests, since a supermarket provides jobs that are less likely to be dead-end ones and are almost certainly better paid.
Nicholas du Quesne Bird