Potential retail or related real estate development sites are identified using computer databases and algorithms to derive normative association between the supply and demand characteristics of certain trade areas. For a particular site location, the method identifies the most suitable square footage amount for retail or related real estate development. For a particular shopping center, the method identifies individual tenants that are most suitable for inclusion at the particular location. Further, in another embodiment there is provided a method which identifies existing facilities in the nation or region that are most analogous thereby providing a means of forecasting sales for new real estate development.