The data envelopment analysis （DEA） model is used to evaluate the relative economic efficiency of a given set of decision making units （DMUs）. In this paper, the DEA production possibility set is transferred from ...The data envelopment analysis （DEA） model is used to evaluate the relative economic efficiency of a given set of decision making units （DMUs）. In this paper, the DEA production possibility set is transferred from the conventional sum form into the intersection form which is represented by a linear inequality system. Although it is time consuming to obtain the intersection form of the production possibility set, it suggests a new angle to investigate the properties of DMUs and to extend the DEA research further beyond the efficiency measurement. Following the intersection form, the analytical formula of the efficiency indicator and projection is given. Various aspects of technical efficiency, returns to scale and evidence of congestion of the DMUs are studied. The relationship between the weak DEA efficiency and the weak Pareto solution is discussed. Finally, a procedure for DMU grouping is proposed to help the decision makers for better resource reallocation and strategy adjustment.展开更多
This research proposes a new method to estimate returns to scale(RTS) of decision making units(DM Us) with multiple inputs and outputs.The state of return to scale includes increasing RTS,constant RTS,decreasing RTS a...This research proposes a new method to estimate returns to scale(RTS) of decision making units(DM Us) with multiple inputs and outputs.The state of return to scale includes increasing RTS,constant RTS,decreasing RTS and evidence of congestion.The method is based on the production possibility set in the intersection form given by a set of linear inequalities.We propose and prove the necessary and sufficient conditions for the RTS estimation.With the new procedure,to estimate the RTS of a DM U is simply to check the position of the DM U on the production frontiers.We point out that the procedure is particularly important for dealing with a large number of DM U s.Therefore,it can be regarded as a complementary to the data mining.展开更多
This paper gives a dynamic concept and a new non-parametric method for evaluating returns to scale（RTS） of economic units with multiple inputs and outputs.It is frequently noticed that when we increase the input of ...This paper gives a dynamic concept and a new non-parametric method for evaluating returns to scale（RTS） of economic units with multiple inputs and outputs.It is frequently noticed that when we increase the input of a decision making unit（DMU） with a certain status of RTS,different status of RTS is observed.For example,when we increase the input of a DMU with constant RTS under the traditional method,a decreasing RTS is often observed instead of the expected constant RTS.We thus define the RTS of each DMU in both input expansion and contraction regions respectively.The research starts from transferring the production possibility set into the intersection form,by giving the explicit linear inequality representation of production frontiers.The RTS structural characteristics of DMUs＇ on the production frontier are described.Status of RTS of those DMUs on the production frontier include increasing RTS,constant RTS,decreasing RTS,saturated RTS and evidence of congestion.Necessary and suficient conditions for RTS evaluation are provided.The definition and evaluation method given here provide more detailed economic characteristics of DMU for policy makers.展开更多
基金This research is supported by the National Natural Science Foundation of China under Grant Nos. 70531040, 70871114, and the 985 Research Grant of Renmin University of China, and the Hong Kong CERG Research Fund PolyU5457/06H and PolyU 5485/09H.
文摘The data envelopment analysis （DEA） model is used to evaluate the relative economic efficiency of a given set of decision making units （DMUs）. In this paper, the DEA production possibility set is transferred from the conventional sum form into the intersection form which is represented by a linear inequality system. Although it is time consuming to obtain the intersection form of the production possibility set, it suggests a new angle to investigate the properties of DMUs and to extend the DEA research further beyond the efficiency measurement. Following the intersection form, the analytical formula of the efficiency indicator and projection is given. Various aspects of technical efficiency, returns to scale and evidence of congestion of the DMUs are studied. The relationship between the weak DEA efficiency and the weak Pareto solution is discussed. Finally, a procedure for DMU grouping is proposed to help the decision makers for better resource reallocation and strategy adjustment.
基金supported by National Natural Science Foundation of China (Grant Nos.70531040,70871114)The Hong Kong CERG Research Fund (Grant Nos.5485/09H,5515/10H)
文摘This research proposes a new method to estimate returns to scale(RTS) of decision making units(DM Us) with multiple inputs and outputs.The state of return to scale includes increasing RTS,constant RTS,decreasing RTS and evidence of congestion.The method is based on the production possibility set in the intersection form given by a set of linear inequalities.We propose and prove the necessary and sufficient conditions for the RTS estimation.With the new procedure,to estimate the RTS of a DM U is simply to check the position of the DM U on the production frontiers.We point out that the procedure is particularly important for dealing with a large number of DM U s.Therefore,it can be regarded as a complementary to the data mining.
基金supported by the National Natural Science Foundation of China (No. 70531040 and 70871114)the 985 Research Grant of Renmin University of Chinasupported by the Hong Kong CERG Research Fund PolyU 5515/10H and PolyU 5485/09H
文摘This paper gives a dynamic concept and a new non-parametric method for evaluating returns to scale（RTS） of economic units with multiple inputs and outputs.It is frequently noticed that when we increase the input of a decision making unit（DMU） with a certain status of RTS,different status of RTS is observed.For example,when we increase the input of a DMU with constant RTS under the traditional method,a decreasing RTS is often observed instead of the expected constant RTS.We thus define the RTS of each DMU in both input expansion and contraction regions respectively.The research starts from transferring the production possibility set into the intersection form,by giving the explicit linear inequality representation of production frontiers.The RTS structural characteristics of DMUs＇ on the production frontier are described.Status of RTS of those DMUs on the production frontier include increasing RTS,constant RTS,decreasing RTS,saturated RTS and evidence of congestion.Necessary and suficient conditions for RTS evaluation are provided.The definition and evaluation method given here provide more detailed economic characteristics of DMU for policy makers.
