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
