Bob, We *do* all trade with our neighbors so your term is only trouble when looking at the wrong part of the geometry. With trade the measure should not be based on physical space or network geometry, those are transient and permutable, rather the measure should be based on the proximity of the parties in terms of goods consumed, goods produced and pricing. The networks are not electrical or geographical they're economic. So while it does affect cost all this communication and transportation technology is only the physical layer. Mike