Public policy change and its impact on urban expansion: an evaluation of 265 cities in China

Public policies play a vital role in shaping our cities. However, the impact of public policies on the spatial expansion of urban areas needs to be better understood in order to achieve better policy outcomes. During the period of China's economic reform, the central government of China has made many changes in three sets of public policies—regional development policies, the household registration (hukou) system, and urban land and housing market policies—to promote coordinated development of small, medium and large cities. This study aims to examine the effects of these public policy changes on urban expansion across 265 Chinese cities at or above prefecture level. We first quantify the spatial patterns of urban areas and evaluate the extent of urban sprawl of the 265 cities from 1995 to 2015 using multi-temporal land cover data. These cities are classified into six categories according to a city tier system used in China. Through a set of individual fixed-effects models, we then explore how changes in the three sets of policies have influenced urban expansion differently across different-tier cities. Results show that sprawling patterns of urban expansion, which have been more prominent in small and medium sized cities since 2000, are associated with shifts in policies to support stronger economic and population growth as well as real estate development. Our findings highlight the need for policymakers to take a holistic approach by considering the size of cities together with their social, environmental, and economic characteristics in order to minimise inequality and achieve coordinated urban development goals