Urbanization bubble: Four quadrants measurement model

• Define urbanization bubble from perspectives of population, land use, industrial development, and infrastructure development.
• Identify urbanization rate and four performance variables for measuring urbanization bubble.
• Introduce a coordinate method for measuring urbanization bubble.
• Give a case study to verify the effectiveness of this coordinate method.

The proper understanding of the urbanization bubble is very important to assist local governments in adopting strategies to mitigate the effects of the bubble and guide urbanization toward sustainable development. This paper presents a method of measuring the urbanization bubble with particular reference to China. In referring to the definition of an economic bubble, this study defines the urbanization bubble as a dynamic process in which urbanization rate (UR) deviates from four urbanization performance variables comprising the proportion of urban population with registration (TRP), urban construction land area (TBA), level of industrial development (LID) and level of public facilities (LPF). Four coordinates are formed between the rate of urbanization and the four performance variables to examine the practice of urbanization in terms of four quadrants. The ratios between changes in urbanization rate and the changes of the four urbanization performance variables are introduced to measure the urbanization bubble. The method is tested through a case study to show that the coordinate method has the potential to help policy makers detect any bubble in the process of urbanization.