贸易成本、技术溢出与环境污染

经济地理稳定均衡是由区内外多种力量共同作用的结果，本文的研究不再把区域视为没有空间维度的"点"，而是认为区内外均存在贸易成本，且技术溢出、环境污染在区内外也有差别。在考虑这些因素的基础上，本文发展的新经济地理学模型得出的研究结论表明：（1）本地技术溢出效应或跨界环境污染效应的增加，有利于产业的集聚；反之，本地环境污染效应或跨界技术效应的增加，有利于产业的分散布局。区内贸易度的增加，也有利于产业的分散布局。当工业品替代弹性过低或过高时，中心—外围结构都可能是稳定的均衡结构。（2）在一定的贸易自由度范围内，不仅可能出现内部非对称结构为稳定均衡的情形，也可能出现内部非对称结构与中心—外围结构或对称结构与中心—外围结构稳定均衡共存的情形。（3）当贸易自由度较低或较高时，对称结构都可能是稳定均衡结构，甚至只要满足一定的条件，无论贸易自由度如何变动，对称结构均为唯一的稳定均衡结构。

Trade cost,Technology Spillover,and Environmental Pollution

The equilibrium structure of economic geography is the result of combined effect of both internal and external forces, so this paper no longer regards region as "point" without spatial dimensions and holds that trade cost exist in both inside and outside of the region, and local technology spillover effect and environmental pollution effect are also different within and outside a region. Based on these foundations, the new economic geography model developed in this paper shows that:Firstly, the strengthening of local technology spillover effect and trans-boundary environmental pollution effect promotes industrial agglomeration whereas the strengthening of local environment pollution effect and the trans-boundary technology effect lead to industrial dispersion, and the increase of intraregional trade freeness also help to form a decentralized spatial pattern. In addition, the core-periphery equilibrium may be exist under the circumstance that the substitution elasticity between industrial goods is too low or too high. Secondly, not only can the stable internal asymmetric equilibrium exist alone, but also co-exist with the internal asymmetric and core-periphery equilibrium or with the symmetric and core-periphery equilibrium when the trade freeness is within a certain range. Thirdly, the stable symmetric equilibrium may exist in both situations whether trade freeness is low or high, even under certain conditions, the symmetric structure is the only stable equilibrium structure no matter how the trade freeness changes.