中产阶层化是城市居住空间分异研究的前沿领域,而“租差”是解读中产阶层化现象的核心概念。通过对Smith“租差”模型的借鉴与修正,提出中国政治经济制度转轨背景下,“租差”是由土地公有和房屋贬值产生的“实际租差”和房地产持续快速增值产生的“预期租差”两部分组成。在此基础上,以南京内城和典型中产阶层化区域为例,利用2001-2011年间房屋拆迁及补偿、土地出让与利用方式转变、住宅价格变动等数据,通过刻画城市更新运动中“租差”扩大与资本化实现、物质空间环境改善、邻里社会结构跃升和阶层置换过程,分析南京内城中产阶层化现象和“租差”的核心驱动作用。最后在揭示中产阶层化作为深度城市化手段和空间再生产策略的同时,批评其对城市传统文化的“创造性破坏”,以及“租差”收益再分配中对被拆迁贫困群体的多重剥夺问题。

Gentrification is a frontier field of urban residential differentiation, while the rent gap is a core concept to interpret the phenomenon of gentrification. Through reference, analysis and correction to the rent gap model proposed by Smith, this paper puts forward a classical rent gap theory model different from the Western premises of complete marketization and private ownership of land. In China, rent gap consists of two parts, i.e. "actual rent gap" generated by the public ownership of land and the housing depreciation, and "rent jump" generated by the continuous rapid appreciation of real estate. Both are generated under the background of the political and economic system transition, including the decentralization of the central government, the enterprisation of local government, the marketization of land and housing. Based on this, the paper takes the inner city of Nanjing and "Liji Lane Plot", a typical gentrification area, as an example, and makes use of data such as the housing demolition and compensation, changes in the modes of land transfer and land use, housing price change and other data, in order to analyze and validate the gentrification phenomenon of inner city of Nanjing and the driving effects of the rent gap by describing rent gap practices, environmental improvements and gentrification replacement processes in the demolition and reconstruction of urban areas. The empirical study indicates that: (1) driven by the rent gap interest and dominated by the urban growth coalition, over 150 plots in the inner city of Nanjing have realized high-end reconfiguration in terms of built environment and social class structure by "demolishing the old and building the new"; (2) in the principle of the maximum rent gap, some areas have become hot spots of gentrification, including the areas of Confucius Temple in the south of the city, Xiaguan in the north of the city, Xinjiekou in the central city, and areas along main roads and on both sides of the Qinhuai River, due to sufficient profit margin between land redevelopment cost and expected return; (3) in the screening mechanism of the price of reconstructed commodity housing, over 18,700 needy families unable to move back have been passively moved from the inner city to the urban fringe, and the renewed location in the inner city are occupied by the emerging middle class. When we affirm the gentrification as a means of deep urbanization and a strategy for reproduction of space, gentrification should also be criticized for its damage to the traditional culture of the city and multiple deprivation of the original needy residents in the redistribution of rent gap income.