Technological Change and the Concentration of the U.S. General Cargo Port System: 1970-88
研究了1970-1988年间集装箱化等四项技术变革如何导致美国通用货物港口交通集中化，并解释了与集装箱货物分散化趋势看似矛盾的现象。
AbstractThe diffusion of containerization has changed not only how general cargo is handled, but where. Using the Gini coefficient, we show that general cargo port traffic has become more concentrated from 1970 to 1988 because of four technological changes: containerization, larger ships, larger trains, and computerization of freight tracking and billing. These four technological changes have spawned four kinds of intermodal services: microbridge, minibridge, landbridge, and round-the-world. We reconcile this concentration trend with Hayuth's (1988) seemingly contradictory finding that containerized cargo, which makes up most of general cargo, became less concentrated throughout the U.S. port system from 1970 to 1985. Anticipated future technological innovations are expected to continue the concentration trend. Our results fit well into Slack's (1990) proposed addition of a seventh stage (dropping of redundant nodes) to the Taaffe, Morrill, and Gould (1963) model of network development. In a methodologica...