中文摘要：

撤县（市）设区是通过打破行政区经济，减少行政区边界，实现以地级市为基础的经济一体化的重要手段，采用政策评估的常用工具——倍差法，对中国1990．2007年的撤县（市）设区的样本进行了分析，发现撤县（市）设区对城市经济增长具有约5年的短期促进作用，主要表现在人均GDP增长率、人均固定资产投资增长率、人均消费增长率等方面，对人均道路面积和人均公共汽车数量的增长率则是先抑后扬，对相邻城市的经济增长则具有约2年的短期促进作用；并以佛山撤县（市）设区为案例，分析了短期促进作用的来源和长期激励消失的原因，认为基础设施投资是政府在撤县（市）设区后的主要行为，以此带动产业转移和房地产消费，进而促进了经济增长；但由于撤县（市）设区削弱了地方政府的发展权限，向上级政府集中了资源的控制权，使得地方长期经济发展的激励消失。

英文摘要：

In order to accomplish economic integration of prefecture, turning counties into districts dominates policy instruments of prefecture-level governments in way of breaking the administrative economy and reducing administrative borders. However, our research casts doubt on this policy instrument. In this paper we have introduced the DID （difference in difference） method which is generally applied in policy evaluation area, to analysis the city sample of turning counties （cities） into districts between 1990 and 2007 in China. And we have found the policy of turning counties （cities） into districts only have short-term effect in promoting the cities＇ economic growth in about 5 years, which embodied in certain indicators - per capita GDP growth, per capita growth rate of fixed asset investment, per capita consumption growth, etc. As for the growth rate of per capita road area and per capita of the number of buses, the effect is the first decline after rally, while the effect on adjacent cities＇ economic growth only lasted two years. In second part, the case study of Foshan is launched to explain causes for above-mentioned short-term rather than long-term incentive. We claim that investing in the cities＇ infrastructure will be local governments＇ primary behavior after the policy of turning counties （cities） into districts, and this behavior will promote industrial transfer and stimulate the real estate market, thus contributing to the cities＇ economic growth. However, turning counties into districts discourages county-level development by centralizing prefecture-level governments＇ control rights over resources and weakening development rights of county government. So we conclude the process to the regional economic integration by administrative means only have short-term effect because of the disappearance of long-term incentives.