上市港口企业投人产出效率研究

运用三阶段DEA模型，对在上海证券交易所上市的港口企业投入产出效率进行研究．基于上市港口企业年报数据，选取港口营业成本和在职员工数作为投入指标，选取港口货物吞吐量和净利润作为产出指标，构建基于港口企业运营特点的DEA模型；引进环境变量，采用SFA模型分解DEA模型中投入指标的松弛变量；重新运行经调整后的投入指标与原产出指标的DEA模型．研究结果表明，2012年我国上市港口企业整体综合效率水平相对较高，投入冗余程度相对较轻，对于部分规模报酬递增型港口可以考虑适度扩大规模，对于综合效率低于平均水平的部分港口，应考虑寻找企业内部运营管理问题，适度减少投入．

Research on the Input-Output Efficiency of the Listed Port Enterprises

The three-stage DEA（data envelopment analysis） model is used to study the input-output ef-ficiency of port enterprises, which is listed on the Shanghai Stock Exchange. The input-output DEA model is build ,which is based on the operating characteristics of port,to analysis of the input-output efficiency of the decision making units, using the port operating cost and the staff number as the in-ptts and the port cargo throughput and the net income as the outputs. The SFA（stochastic frontier a-nalysis） model is build to decompose the slack variable of the inputs , and eliminate the influence of environmental impacts and random disturbances. The adjusted inputs and the original outputs are used to rerun the DEA model, with the purpose of analyzing the final input-output efficiency. The results show that the overall input-output efficiency of port enterprises listed on the Shanghai Stock Exchange is relatively high,and the input redundancy level is relatively low in the year of 2012. For some ports with increasing returns to scale can be considered to moderately expand the scale of the port,and for some port, whose comprehensive efficiency is lower than the average, should be considered to look for the internal causes of the enterprise＇s operation and management,and moderately reduce the investment.