“…Beyers (1974Beyers ( , 1981, Campbell (1972Campbell ( , 1974Campbell ( , 1975, Erickson (1975), Moore (1972Moore ( , 1973, and Schmidt (1975) have all attempted to describe processes of polarization, interconnection, and extra-regional linkage in specific territorial settings. Similar work has been carried out on the structure of metropolitan input-output systems by Artle (1965), Isard et al (1972), Hirsch (1959), Karaska (1966Karaska ( , 1969, Morrison (1973aMorrison ( , 1973bMorrison ( , 1973c, and Walker (1977). Much of this work on the metropolitan economy has uncovered the existence of very significant demand and supply leakages beyond the boundaries of any given metropolitan area.…”