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准确估计港口对区域经济的贡献是明确其在港口城市中心地位的关键.针对在市场经济条件下造成的港口投资不确定因素，考虑随着时间推移不确定因素的变化，将港口经济贡献和多年时滞港口投资问题联系起来，引入多年时滞投资系数，建立一种改良后可计算的多年时滞的港口经济贡献动态投入产出模型.运用该模型对上海港的经济贡献进行动态滚动式估算，得到有益的结果，验证了模型的可操作性和实用性.

Multi-Year Time Lag Dynamic Input-Output Model on Port Economic Contribution

Accurate measurement of the contributions of the port to regional economy is the key to determine port’s central position in the city. Considering some uncertain factors in port investment, the paper proposes a computable and improved model on port economic contribution. In which, the economic contribution of port and the problem of multi year time lag investment are involved and the investment coefficient is introduced relating to market economy of port. This paper takes Shanghai port as an example to dynamically estimate the economic contribution of rolling. The result shows that the proposed model is practicable and effective.