Given an urban area such as a shopping mall, is there a statistical model that estimates how often during a working day the area becomes depopulated and what is the maximum time of depopulation?
By depopulation I mean that the number of people per unit area becomes zero.
In particular I am interested to know the answer to this question: Can we say that typical urban areas are usually populated (during the working day) and there is an upper-bound for the depopulation time? any article that exposes some research regarding this subject would be useful.