纵向范围经济的估算——基于燃气行业纵向分离改革的实证研究

An Estimation of the Degree of the Vertical Economies of Scope——Based on the Reform of the Vertical Separation in the Gas Industry

本文基于2001～2007年中国19家燃气企业层面的数据,结合2000年底上海燃气行业进行的产销纵向分离的改革,采用数据包络方法对纵向一体化和纵向分离产生的纵向范围经济进行了估算.结果表明,2001～2007年全样本13家纵向一体化燃气企业EVI的均值为1.1434,总体表现为纵向范围不经济,而当样本分为2001～2004年和2005～2007年两个子样本时,发现2001～2004年13家纵向一体化燃气企业总体呈现较弱的纵向范围经济,EVI的均值为0.9806,而2005～2007年13家纵向一体化燃气企业总体呈现较强的纵向范围不经济.

Based on the data of 19 gas enterprises from 2001 to 2007 in China and combining the reform of vertical separation in Shanghai gas industry in 2000, this paper estimates the vertical economies of scope generated from vertical in- tegration and vertical separation by means of data envelopment analysis. The results reveal that the mean of EVI of the full sample 13 vertically integrated gas enterprises from 2001 to 2007 is 1. 1434 ,thus vertical economies of scope does not ex- ist. However,when the sample is divided into 2001 -2004 and 2005 -2007 sub-samples, it can be found that the EVI mean of 13 vertically integrated gas enterprises is 0. 9806 in 2001 -2004 and overall shows weak longitudinal extent econ- omies,while in 2005 -2007 shows strong longitudinal extent diseconomies