经济学院知识库

在我国经济发展仍主要依靠城市化带动的背景下， 城市规模扩张是促使投资、出口和内需带动经济效率提高的重要影响因素， 住房价格既能够通过财富效应增加家庭消费以及实物资产投资促进经济增长， 然而其也具有负外部性即造成资源错配现象降低城市经济增长效率。基于循环积累因果理论的城市集聚经济，城市规模变化是拥挤效应和规模经济下的权衡机制， 住房价格高企使得购买力不足的人群退出高房价区域从而实现城市规模调整。 我国区域间和城市内部之间因城乡二元经济结构以及户籍制度存在显著差异， 如何推动城市规模扩张并有效规避因资本逐利性而引致激增的住房投资性需求， 对于探究住房价格与城市规模因素对经济效率变化的影响具有重要意义， 对于丰富城市经济效率提升和该主题的深入研究，具有重要理论价值。 

本研究通过收集 285 个地级市及以上 2000-2017 年的面板数据， 利用扩展空间交互理论模型解析影响路径，基于非期望产出 SBM 模型测算经济效率，使用ArcGIS 软件刻画主要变量在代表性年份的时间和空间变化趋势，并运用固定效应模型和双重差分法（DID）实证分析住房价格与城市规模对经济效率的协同影响， 使用门槛回归模型检验是否存在非线性关系，最后利用中介效应模型检验城市规模在住房价格对城市经济效率间的中介效应。主要研究结论和启示为： 

（1）全样本回归发现住房价格对经济效率的提高具有阻滞效应，而城市规模扩大能够带动经济效率增长。通过门槛回归发现，住房价格在城市规模扩张初期表现为消极的抑制作用，反而在城市规模扩张中期表现出积极的增促作用，继而在城市规模达到峰值时仍未正向作用但程度明显下降； 

（2）使用双重差分法（DID）将限购政策纳入模型中虽未改变住房价格对经济效率的抑制作用，但限购政策显著缓解了抑制程度，特大规模城市的高房价导致资金流向房地产行业，挤占城市创新资金，限购政策缓解住房投资性需求对经济效率提升的基础效应； 

（3）中介效应模型回归结果表明，城市规模作能够显著缓解住房价格对经济效率提升的阻滞作用，限购政策虽然无法改变大城市高房价上涨趋势，但住房投机性需求得到压制，在住房刚需不变的情况下，住房价格对经济效率的抑制强度可能会保持不变或下降，而城市规模的集聚效应在增强，整体对经济效率的增促效果在增强； 

（4）异质性分析表明，十大城市群经济发展水平层次不齐，京津冀、长三角和珠三角区域，经济发展水平居高不下，住房价格与城市规模早已超出正常范围对经济效率表现出显著抑制作用， 需要依赖创新驱动和产业结构优化等途径提高经济效率。 

总体而言，在我国经济进入“双循环”新发展格局的形势下，关注关乎国计民生的住房价格和城市规模变动问题，并聚焦于二者对城市经济效率的影响，对于区域经济社会实现面向更加充分和平衡的发展而言具有重要意义。

Under the background that my country's economic development is still mainly driven by urbanization, the expansion of urban scale is an important factor that promotes investment, exports and domestic demand to drive economic efficiency. Housing prices can increase household consumption through the wealth effect and investment in physical assets can promote economic growth. However, it also has negative externalities that cause resource misallocation and reduce the efficiency of urban economic growth. Urban agglomeration economy based on the theory of circular accumulation of causality, the change of city scale is a trade-off mechanism under the congestion effect and economies of scale. High housing prices make people with insufficient purchasing power to withdraw from areas with high housing prices to achieve urban scale adjustment. Due to the significant differences in the urban-rural dual economic structure and the household registration system between regions and cities in my country, how to gradually promote the expansion of urban scale and effectively avoid the surge in housing investment demand caused by the profit-seeking of capital? The influence of urban scale factors on changes in economic efficiency is of great significance, and it has important theoretical value for enriching the improvement of urban economic efficiency and in-depth research on this topic.

This study collects panel data from 285 prefecture-level cities and above from 2000 to 2017, uses the extended spatial interaction theory model to analyze the influence path, measures economic efficiency based on the undesired output SBM model, and uses ArcGIS software to characterize the main variables in a representative year. Empirical analysis of the synergistic effect of housing prices and city size on economic efficiency using fixed effects models and double difference method (DID), using threshold regression models to test whether there is a non-linear relationship, and finally using a mediation effect model to test The mediating effect of city size in housing price and city economic efficiency. The main research conclusions and inspirations are:

(1) The full-sample regression found that housing prices have a blocking effect on the improvement of economic efficiency, and the expansion of urban scale can drive economic efficiency growth. Through the threshold regression, it is found that the housing price has a negative inhibitory effect in the initial stage of urban scale expansion, but has shown a positive boosting effect in the middle of urban scale expansion, and then has no positive effect when the city scale reaches its peak, but the degree is significantly reduced;

(2) The use of double difference method (DID) to incorporate the purchase restriction policy into the model has not changed the inhibitory effect of housing prices on economic efficiency, but the purchase restriction policy has significantly eased the degree of inhibition. The high housing prices in very large cities have led to capital flow to the real estate industry and squeezed Urban innovation funds and purchase restriction policies alleviate the fundamental effect of housing investment demand on economic efficiency improvement;

(3) The regression results of the intermediary effect model show that urban scale operations can significantly alleviate the blocking effect of housing prices on economic efficiency. Although the purchase restriction policy cannot change the upward trend of high housing prices in big cities, the speculative demand for housing has been suppressed. In the case of unchanged, the restraining intensity of housing prices on economic efficiency may remain the same or decrease, while the agglomeration effect of urban scale is increasing, and the overall effect of promoting economic efficiency is increasing;

(4) The analysis of heterogeneity shows that the economic development level of the ten major urban agglomerations is not uniform. The economic development level of the Beijing-Tianjin-Hebei, Yangtze River Delta and Pearl River Delta regions remains high. Housing prices and urban scale have long been beyond the normal range, which is important for economic efficiency. Exhibiting a significant inhibitory effect, it is necessary to rely on innovation-driven and industrial structure optimization to improve economic efficiency.