The research reported in this book began as part of a Ph. D. dissertation submitted to the University of Pittsburgh in 1976. Revisions were accomp­ lished at Florida International University in Miami. There have been many people who were instrumental in the formation and completion of this research. The contributions made by Jack Ochs are far too numerous to mention. Jack's insights and suggestions will always be appreciated. I am also grateful to Melvin Greenhut, David Houston, Tatsuhiko Kawashima, Asatoshi Maeshiro, William Miernyk, Josephine Olson, Peter Nijkamp and Harry Richardson who read and critically re­ viewed earlier manuscripts. I am doubly indebted to Harry Richardson who