我国拖拉机制造业市场集中度研究

Study on concentration ratio of tractor manufacturing industry in China

针对我国拖拉机制造业产能过剩和生产集中并存的问题,运用产业组织相关理论,利用2004和2005全年,以及2006年1—9月份的销量和产量数据对拖拉机制造业整体和分支行业的市场集中度进行研究。通过测算集中度系数、赫芬达尔-赫希曼指数(HHI)、因托比指数(E.I)、洛伦兹曲线和基尼系数(G.I),判定拖拉机制造业整体与分支行业的市场结构类型。结果表明:1)我国拖拉机制造业前4家企业的集中度系数由43.82增至66.09,HHI由0.1773增至0.1907,E.I逐年减少,洛伦兹曲线偏离绝对平均线程度愈加明显,G.I维持在0.7左右,由此判定我国拖拉机制造业整体市场结构属于垄断型,企业规模差距逐渐增大;2)大中型拖拉机制造业市场结构属于垄断型,且程度逐年加深,企业规模差距由较为平均变为差距较大;3)小型拖拉机制造业市场结构属于竞争型,且有向垄断型发展的趋势,企业规模由分布平均变为差距较大;4)拖拉机制造业整体市场结构由低垄断向高垄断转型,分支行业中寡头垄断与过度竞争并存,市场势力相差悬殊。

Based on the fact that the coexistence of overcapacity and production concentration,this paper analyzed the concentration ratios of Tractor Manufacturing Industry（TMI）and its branches in China by the data of sales and yields in 2004,2005 and 2006（from Jan.to Sep.）.By means of evaluating the concentration ratio,Herfindahl-Hirschman Index（HHI）,Entropy Index（E.I）,Lorentz Curve and Gini Coefficient（G.I）,the whole market structure of TMI and its branches in China were estimated.The results showed that the concentration ratios of the top 4 of TMI increased from 43.82 to 66.09;the HHI increased from 0.177 3 to 0.190 7;the E.I reduced year after year;the deviation degree of the Lorentz curve with absolutely and mean line was clear;and G.I kept to 0.7.These indicated that the market structure of TMI was monopolistic and the gap among enterprise scale had become wider.The market structure of medium and large TMI was monopolistic,the degree of monopoly was stronger and the gap among enterprise scale changed from relatively average to wider.The market structure of small TMI was competitive and to be the tendency of monopoly,the degree of monopoly was stronger and the gap among enterprise scale changed from average to wider.The market structure of TMI was in the period of transformation from low monopolization to high monopolization,and there was coexistence of oligopoly and excessive competition in the market of branch industry,and a great gap among the market powers.