The settlements that Bloomberg has been getting so far are tiny and simply represent these stores getting rid of cases that involve significant legal costs. But Bloomberg might run into some trouble with a second lawsuit being filed against him and NYC.
As Rich, who provided me with this link, wrote: "Gun control will never succeed simply because guns can be manufactured at home with a few tools as illustrated in this article." Thanks for sending this, Rich.
This is something that I don't believe that I have seen studied in an academic paper. Steve Bronars and I have a paper on geographical movement of crime in the May 1998 AER, but that is the closest thing that I know of.