Has anyone seen a table that would provide an estimate of retail jobs per square foot of space, or the inverse? For example, a downtown retail storefront of 1,000 square feet can expect approximately XX employees?
I doubt any such thing exists. There is very little corelation between the size (space) of a business and the number of employees. It is very much dependant upon the typs of business and the level of business, or traffic that a store would expect.
I have a great deal of info on what you are looking for. We did a study here (Vail, Colorado) to determine what our local rates are for employee generation by land use. We assess an employee housing requirement for new development based on our figures. There is a very significant correlation between the size of a business and the number of employees it will generate.
I'd be happy to supply you with copies of what we do, but I am afraid it would only be relevant to our specific local resort needs. Drop me an e-mail if you want to take a look though. Good luck.
Chapin, Kaiser, and Godschalk (Urban land use planning, 1995) address how to do this on p. 329. Basically, the short cut way is to get total employment data by category, and divide the number of employees by acres of land use in that employment category to get a rate of employees per acre. This source also notes that years ago the gross employment density in Charlotte ranged from 8.9 employees per acre in the outer, newer employment centers to 51 in the central business district.
I'm not sure I can fully justify it, but office workers use about 200 or 300 square feet of space per employee, and if you had gross square footage data you could use that. Retail would be higher, but I don't know exactly how much. See also the discussion about industrial employment densities in Urban Land Use Planning, p. 330. 8 per acre is a reasonable suburban ballpark figure and the range has been shown to be from as low in Phoenex to as high as 24 per acre for industrial employment. Since employment density will vary from place to place it is best to do a local study.